Category: Class 12

MP Board Class 12th Chemistry Important Questions Chapter 7 The p-Block Elements

The p-Block Elements Important Questions

The p-Block Elements Objective Type Questions

Question 1.
(A) Choose the correct answer :

Question 1.
In which compound oxygen exhibits +2 oxidation state :
(a) H₂O
(b) Na₂O
(c) OF₂
(d) MgO.
Answer:
(c) OF₂

Question 2.
Reddish brown gas is formed, when nitric oxide oxidizes by air. This gas is :
(a) Na₂O₂
(b) Na₂O₄
(c) NO₂
(d) N₂O₃.
Answer:
(c) NO₂

Question 3.
H₃PO₃ is :
(a) Dibasic acid
(b) Monobasic acid
(c) Tribasic acid
(d) Tetrabasic acid.
Answer:
(c) Tribasic acid

Question 4.
Oxide which shows paramagnetic character :
(a) N₂O₄
(b) NO₄
(C) P₄O₆
(d) N₂O₅
Answer:
(b) NO₄

Question 5.
Ammonia can be dried by :
(a) H₂SO₄
(b) P₂O₅
(c) Anhydrous CaCl₂
(d) CaO.
Answer:
(d) CaO.

Question 6.
Nitric acid change iodine into :
(a) Iodic acid
(b) Hydroiodic acid
(c) Iodine pentaoxide
(d) Iodine nitrate.
Answer:
(a) Iodic acid

Question 7.
NH₃ is a Lewis base which forms complex salt with cations. Following cation does not form complex salt with NH₃ :
(a) Ag⁺
(b) Cu2⁺
(c) Cd2⁺
(d) Pb2⁺.
Answer:
(d) Pb2⁺.

Question 8.
Ammonia is soluble in :
(a) Hg₂Cl₂
(b) PbCl₂
(c) Agl
(d) Cu(OH)₂.
Answer:
(d) Cu(OH)₂.

Question 9.
Bleaching action of SO₂ is due to :
(a) Reduction
(b) Oxidation
(c) Hydrolysis
(d) Acidic nature.
Answer:
(a) Reduction

Question 10.
What happens when SO₂ is passed through acidic K₂Cr₂O₇ :
(a) Solution turns blue
(b) Solution turns colourless
(c) SO₂ reduced
(d) Green chromic sulphate is formed.
Answer:
(d) Green chromic sulphate is formed.

Question 11.
P₂O₂ forms which of the following acid :
(a) H₄P₂O₇
(b) H₃PO₄
(c) H₃PO₃
(d) HPO₃.
Answer:
(c) H₃PO₃

Question 12.
Most acidic halide is :
(a) PCl₅
(b) SbCl₃
(c) BrCl₃
(d) CCl₄
Answer:
(a) PCl₅

Question 13.
The catalyst used in manufacturing of H₂SO₄ is :
(a) Al₂O₃
(b) CrO₃
(c) V₂O₅
(d) MnO₂
Answer:
(c) V₂O₅

Question 14.
The hydrolysis of phosphorus triha lides give:
(a) One monobasjc acid and one dibasic acid
(b) One monobasjc acid and one tribasic acid
(c) One monobasjc acid and a salt
(d) Two dibasic acids.
Answer:
(a) One monobasjc acid and one dibasic acid

Question 15.
In the following reaction:
P₄ + 3NaOH + 3H₂O → PH₃ + 3NaH₂ PO₂
(a) P oxidises
(b) P oxidises and reduces
(c) P reduces
(d) Na oxidises.
Answer:
(b) P oxidises and reduces

Question 16.
Laughing gas is:
(a) NO
(b) N₂O
(c) N₂O₃
(d) N₂O₅.
Answer:
(b) N₂O

Question 17.
White phosphorus does not contain:
(a) 6 P – P single bond
(b) 4 P – p single bond
(c) 4 lone pair of electron
(d) Bond angle of P – P – P is 600.
Answer:
(b) 4 P – p single bond

Question 18.
On heating NH₄CI and NaNO₂ solution gives :
(a) N₂O
(b) N₂
(c) NO₂
(d) NH₃.
Answer:
(b) N₂

Question 19.
Formula of metaphosphoric acid is:
(a) H₃PO₃
(b) HPO₃
(c) H₃PO₃
(d) H₂PO₃.
Answer:
(b) HPO₃

Question 20.
Gas which cannot be collected on water:
(a) Na
(b) O₂
(c) SO₃
(d) PH₃.
Answer:
(c) SO₃

(B) Choose the correct answer:

Question 1.
Chlorine shows bleaching property in the presence of :
(a) Dry air
(b) Moisture
(c) Sunlight
(d) Pure oxygen.
Answer:
(b) Moisture

Question 2.
Which of the following element forms least number of compounds :
(a) He
(b) Ar
(c) Kr
(d) Xe.
Answer:
(a) He

Question 3.
Which is used for bright advertisement display :
(a) Xe
(b) Ar
(c) Ne
(d) He.
Answer:
(c) Ne

Question 4.
Monazite is a source of:
(a) Ne
(b) Ar
(c) Kr
(d) He.
Answer:
(d) He.

Question 5.
Which of the following is not obtained by the direct reactions of the constituents :
(a) XeF₂
(b) XeF₄
(c) XeO₃
(d) XeF₆.
Answer:
(d) PbI₄.

Question 6.
Which of the following halides are least stable and whose existence is suspicious :
(a) CI₄
(b) Gel₂
(c) Snl₄
(d) PbI₄.
Answer:
(d) PbI₄.

Question 7.
Which of the following is the strongest acid :
(a) HBr
(b) HCl
(c) HF
(d) HI.
Answer:
(d) HI.

Question 8.
Most electronegative element is :
(a) F
(b) Cl
(c) Br
(d) I.
Answer:
(a) F

Question 9.
Which halogen is solid at room temperature :
(a) Cl₂
(b) I₂
(c) Br₂
(d) F₂.
Answer:
(d) F₂.

Question 10.
Which has maximum electron affinity :
(a) F
(b) Cl
(c) Br
(d) I.
Answer:
(b) Cl

Question 11.
Electronic configuration of valence shell of halogen is :
(a) s²p⁵
(b) s²p³
(c) s²p⁶
(d) s²p⁴.
Answer:
(a) s²p⁵

Question 12.
Which element is most alkaline:
(a) F
(b) Cl
(c) Br
(d) I.
Answer:
(d) I.

Question 13.
The strongest reducing agent is:
(a) F^–
(b) Br^–
(c) I^–
(d) Cl^–
Answer:
(c) I^–

Question 14.
Which of the following is weakest acid:
(a) HF
(b) HCl
(c) HBr
(d) HI.
Answer:
(a) HF

Question 15.
Oxidizing property is highest of:
(a) 12
(b) Br₂
(c) F₂
(d) Cl₂.
Answer:
(c) F₂

Question 16.
Which Noble gas does not have octet complete:
(a) Helium
(b) Neon
(c) Argon
(d) Krypton.
Answer:
(a) Helium

Question 17.
Which Halogen sublimates :
(a) Chlorine
(b) Bromine
(c) Iodine
(d) Fluorine.
Answer:

Question 18.
12 easily dissolve in Kl solution to form :
(a) I
(b) KI₂
(c) KI
(d) KI₃
Answer:
(d) KI₃

Question 19.
Gas mixed in oxygen which is used in respiration for asthma patients :
(a) N₂
(b) Cl₂
(c) He
(d) Ne.
Answer:
(c) He

Question 20.
Deacon’s process is used for manufacture of :
(a) Bleaching powder
(b) Chlorine
(c) Nitric acid
(d) Sulphuric acid.
Answer:
(b) Chlorine

Question 21.
Sea grass is the source of industrial manufacture of :
(a) Chlorine
(b) Bromine
(c) Iodine
(d) Fluorine.
Answer:
(c) Iodine

Question 2.
(A) Fill in the blanks :

1. N₂O is a ……………….. oxide.
2. Formula of Caro’s acid is ………………..
3. Concentrated nitric acid has brown colour due to the dissolution of ……………….. gas.
4. Out of nitrogen oxides ……………….. and ……………….. are paramagnetic.
5. Pyrophosphoric acid is ……………….. basic acid.
6. H₂S gas cannot be dried by cone. H₂SO₄ because H₂S ……………….. it.
7. Fuming sulphuric acid dissolves in SO₃ to form ………………..
8. Oxidation state of S in H₂S₂O₈ (Marshall gas) is ………………..
9. NH₃ gives white fumes of ……………….. when it combines with HCl.
10. Elements of 16^th group are known as ………………..
11. ……………….. is used as a refrigerant.

Answer:

1. Neutral
2. H₂SO₅
3. NO₂
4. NO
5. NO₂
6. Tetra
7. Reduces
8. Oleum
9. +6
10. NH₄Cl
11. Chalcogen
12. Liquid NH₃.

(B) Fill in the blanks :

1. …………………. has the highest electron affinity.
2. In the presence of moisture, chlorine acts as a ………………… agent.
3. Bleaching powder is also called as …………………
4. At ordinaiy temperature bromine is a …………………
5. Inter halogen compound AX₅ has ………………… structure.
6. Chlorine was discovered by …………………
7. Neil Bertlett forms first noble compound which is …………………
8. Element with highest electron affinity is …………………
9. In oxy acid halogen present in ………………… hybride state.
10. Gas which is light due to which it is filled in aircraft tyres is …………………
11. ………………… inert gas is mostly used in advertisements.
12. Elements of Group 17^th are commonly known as …………………
13. ………………… is a radioactive inert gas.

Answer:

1. Chlorine
2. Bleaching
3. Calcium chlorohypochloride
4. Liquid
5. Square pyramidal
6. Scheele
7. Xe [PtF₆]
8. Chlorine,
9. sp³
10. Helium
11. Ne (Neon)
12. Halogen
13. Radon.

Question 3.
(A) Answer in one word / sentence :

1. Who protects earth from ultraviolet rays?
2. Give the chemical name of oil of vitriol or king of chemical.
3. Which gas is used for refrigeration?
4. At which temperature water has maximum density?
5. Give the name of compound formed by the dissolution of S03 in sulphuric acid.
6. Write name of an antichlor.
7. Which gas is used for bleaching of oil and elephant teeth?
8. Ammonium salts react with Nessler’s reagent to give which coloured precipitate?
9. On moving down from N to Bi, +3 oxidation state of Bi becomes more stable than +5. Why?
10. State the percentage of N₂ by volume in nature.

Answer:

1. Ozone layer
2. H²SO⁴
3. NH₃
4. 4°C
5. Oleum
6. SO₃
7. Ozone
8. Brown
9. Due to Inert pair effect
10. 80%.

(B) Answer in one word / sentence :

1. Give the name of radioactive halogen.
2. Which noble gas is used in bulb with nitrogen? (MP 2018)
3. Write the name of noble gas which is used in treatment of cancer.
4. Write the formula of Camalite.
5. Which noble gas is maximum available in the atmosphere?
6. What is the shape of XeF₆?
7. Write one use of fluorine.
8. Which type of hybridization is present in XeO₃?
9. Write the oxidation state of F.
10. Write only equation for the preparation of chlorine in the lab.
11. What is the shape of AX₃ type of Interhalogen compound?
12. Write the correct order of strength of halogen acid.
13. Which noble gases do not form compounds?
14. With which noble gas does F form compounds?
15. Sea weeds are the source of which halogen?

Answer:

1. Astatine
2. Ar
3. Rn
4. KCl.MgCl₂.6H₂O
5. Argon
6. Distorted octahedron
7. In preparing fluorocarbon, which is used in refrigeration
8. sp³
9. -1
10. MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂
11. T – shape
12. HF < HCl < HBr < HI
13. He, Ne and Ar
14. Xe
15. Iodine.

Question 4.
Match the following :
I.

Answer:

1. (d)
2. (c)
3. (a)
4. (b)
5. (f)
6. (g)
7. (e)
8. (i)
9. (j)
10. (h).

II.

Answer:

1. (e)
2. (c)
3. (b)
4. (a)
5. (d)

III.

Answer:

1. (e)
2. (d)
3. (b)
4. (f)
5. (c)
6. (a)

General Principles and Processes of Isolation of Elements Very Short Answer Type Questions

Question 1.
What are clathrate compounds?
Answer:
In the cavity or space of crystal lattice of a compound small sized elements like noble gases get trapped within. Such compounds are called clathrate compounds.
Example : Kr₃ (β – quinol).

Question 2.
Why is BiH₃ the strongest reducing agent amongst all the hydrides of Group 15 elements? (NCERT)
Answer:
Among the hydrides of Group – 15, BiH₃ is the least stable because Bi has largest size in group and has least tendency to form covalent bond with small hydrogen atom. Therefore, it can readily lost H atom and has strongest tendency to act as reducing agent.

Question 3.
Why is N₂ less reactive at room temperature? (NCERT)
Answer:
In N₂ molecule, there is a strong pπ – pπ overlap that results in the formation of triple bond between N atoms (N ≡ N). As a consequence, the bond dissociation energy of N₂ is very high and N₂ is less reactive at room temperature.

Question 4.
Why is Helium used in diving apparatus? (NCERT)
Answer:
Helium is used as a diluent for oxygen is modem diving apparatus because of its very low solubility in blood.

Question 5.
Noble gases are inert. Why?
Answer:
Noble gases are inert due to following reasons :
Noble gases are inert because octet of these gases are complete. It is the most stable state and do not have unpaired electrons. Ionisation energy of noble gases are high and electronegativity and electron affinity are zero. Therefore, these gases neither accept electron nor release electron. Thus, noble gases are inert in nature.

Question 6.
Complete the following reactions: (NCERT)
(i) C₂H₂ + O2 →
(ii) 4AI + 3O₂ →
Answer:

Question 7.
Arrange the following in the order of property indicated for each set: (NCERT)
(i) F₂, Cl₂, Br₂,I₂ – increasing bond dissociation enthalpy.
(ii) HF, HCl, HBr, HI – increasing acid strength.
(iii) NH₃, PH₃, ASH₃, SbH₃, BiH₃ – increasing base strength.
Answer:
(i) I₂ < F₂ < Br₂ < Cl₂

Here F₂ has very less bond dissociation energy inspite of having small size. It is due to repulsion between the lone pair of electrons on small size F – atoms.

(ii) HF < HCl < HBr < HI
It depends upon their bond dissociation enthalpy, which decreases from H – F to H – I as the size of atom increases from F to I.

(iii) BiH₃ < SbH₃ < AsH₃ < PH₃ < NH₃.
They are Lewis bases due to presence of lone pair of electrons on central atom of hydrides. The availability of lone pair of electrons is maximum in nitrogen owing to its small size therefore, NH₃ is maximum basic and as the size of central atom increases availability decreases.

Question 8.
Describe the laboratory preparation of chlorine.
Answer:
Laboratory preparation:
HCl and MnO₂ is taken in a round bottom flask. Cone. HCl is added from thistle funnel. The flask is heated slowly so that green yellow colour of Cl₂ gas evolved.
MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂

Question 9.
Fluorine is strong oxidizing agent as compared to chlorine. Why?
Answer:
Because of following points, fluorine is strong oxidizing agent:

1. The size of F atom is smaller than Cl atom.
2. Electronegativity of fluorine is higher than Cl atom.
3. Dissociation energy of fluorine is less than that of chlorine.
4. E° value of fluorine is more than chlorine.

Question 10.
F₂O is not considered to be the oxide of fluorine. Why?
Answer:
Fluorine is the most electronegative element. Its electronegativity is higher than oxygen. In naming a compound less electronegative elements are first and then more electronegative elements are written, Therefore, F₂O or OF₂ is known as oxygen difluoride and not fluorine oxide.

Question 11.
Interhalogen compounds are more reactive than halogen. Why?
Answer:
X – Y bonds of interhalogen compounds are more polar due to difference in the electronegativities of halogen and are generally weaker than X – Y bonds of pure halogen. Therefore, interhalogen compounds are more reactive than halogens.

Question 12.
Helium and Neon do not form compounds with Fluorine. Why?
Answer:
Due to absence of d – orbitals in the valence shell of He and Ne, their electrons cannot get excited into higher energy d – sub – shells. Therefore, He and Ne do not form compounds with fluorine.

Question 13.
Explain why NH₃ is basic while BiH₃ is only feebly basic. (NCERT)
Answer:
Atomic size of N(70pm) is much smaller than that of Bi (148 pm). Therefore, electron density on the N – atom is much higher than that on Bi – atom. Consequently, the tendency of N in NH₃ to donate the pair of electrons is much higher than that of Bi in BiH₃. Thus, NH₃ is basic while BiH₃ is only feebly basic.

The p – Block Elements Short Answer Type Questions

Question 1.
Explain with reason :

1. HF is liquid while other hydrides of halogens are gases at normal temperature.
2. Fluorine does not form polyhalide.

Answer:
1. The electronegativity of fluorine is maximum than other halogens. Therefore, HF molecule is conjugated by H – bond and the boiling point of HF is more to other halogen acids therefore HF is liquid while halides of other halogens are gases at room temperature.
H – z….H – F….H – F….H – F

2. The electronic configuration of fluorine is 1s², 2s², 2p⁵. Due to absence of orbital in its valency shell it does not show higher oxidation state and so it does not made polyhalide.

Question 2.
How is SO₂ an air pollutant? (NCERT)
Answer:
SO₂ dissolves in rain water and produces acid rain. The acid rain contains sulphuric acid.

In addition to H₂SO₄, acid rain also contains HNO₃.

Question 3.
Why are halogens strong oxidising agents? (MP 2018, NCERT)
Answer:
Halogens are strong oxidising agents due to their low bond dissociation enthalpy, high electronegativity and large negative electron gain enthalpy. Halogens have a strong tendency to accept electrons and thus get reduced.
X₂ + 2e^– → 2X^–
As a result, halogen acts as strong oxidising agents. Their oxidising power however decreases from F₂ to I₂ as is evident from their electrode potentials :
E°_F2/F^– = + 2.87 V
E°_Cl2/Cl^– = + 1.09 V
E°_Br2/Br = +1.09 V
E°_Br2/I = + 0.54 V

Question 4.
Why does the reactivity of nitrogen differ from phosphorus? (NCERT)
Answer:
Molecular nitrogen exist as a diatomic molecule having a triple bond between the two nitrogen atoms, N ≡ N (due to it stability to form pπ – pπ multiple bonding). The bond dissociation energy is very high (941.4 kJ mol^-1). Thus, under ordinary conditions, nitrogen behaves as an inert gas. On the other hand, white and yellow phosphorus exists as a triatomic molecule (P₄) having single bonds. The dissociation energy of P – P bond is low (213 kJ mol^-1). Thus, phosphorus is much more reactive than nitrogen.

Question 5.
Give the reason for bleaching action of Cl₂. (NCERT)
Answer:
Bleaching action of chlorine is due to its oxidation. In the presence of moisture, chlorine gives nascent oxygen.
Cl₂ + H₂O → 2HCl + [O]
Because of nascent oxygen, it bleaches colouring substance as
Colouring substance + [O] → Colourless substance.
It bleaches vegetables or organic matter. The bleaching action of chlorine is permanent.

Question 6.
Explain, why:

1. Noble gases are monoatomic?
2. Atomic radii of noble gases are largest?
3. Ionisation energy of noble gases are highest?

Answer:

1. There is no any unpaired electron in electronic configuration of noble gases. So these do not form chemical bonds and are monoatomic.
2. Outermost shell of noble gases are completely filled so atomic radii of noble gases are maximum.
3. All electrons in outermost orbit of noble gases are paired and energy required to make them unpaired is very high. Thus, noble gases have maximum ionisation energy in respective periods.

Question 7.
Why does nitrogen show catenation properties less than phosphorus? (NCERT)
Answer:
The catenation properties depends upon the strength of the element – element bond. The N – N bond strength is much weaker (due to repulsion of lone pairs on nitrogen because of its small size) than the P – P bond strength, therefore, nitrogen shows catenation less than phosphorus.

Question 8.
Write the formulae and structure of any five oxy – acids of sulphur.
Answer:
Main oxyacids of sulphur and oxidation state of sulphur in them are as follows :

Question 9.
Contact process of manufacturing of H₂SO₄ is supposed to be more advance than lead chamber process. Why?
Answer:

1. The acid obtained by contact process is pure while the acid obtained by lead chamber process is impure.
2. The plant for lead chamber process requires large area while plant used in contact process occupies comparatively less area.
3. The catalyst used in contact process is platinised asbestos while in lead chamber process catalyst is gaseous (NO₂ gas) and to maintain its flow regular is tedious.
4. In contact process concentrated sulphuric acid is obtained while in lead chamber process dilute acid is obtained.
5. In contact process running of the plant is less costly while in lead chamber process running of the plant is costly.

Question 10.
Why does NH₃ form hydrogen bond but PH₃ does not? (NCERT)
Answer:
The N – H bond in ammonia is quite polar as nitrogen is highly electronegative in nature. As a result, NH₃ molecules are linked by intermolecular hydrogen bonding.

On the other hand, P – H bond is non – polar as both P and H have same electronegativity. Hence in phosphine no hydrogen bonding is present.

Question 11.
Bond angle in PH₄⁺ is higher than that in PH₃. Why? (NCERT)
Answer:
PH₄⁺ is a regular tetrahedral structure, thus bond angle is 109°28′.
PH₃ molecule has a pyramidal structure. The bond angle is 93°. Hence, bond angle in PH₄⁺ ion is higher.

Question 12.
What happens when white phosphorus is heated with concentrated NaOH solution in an inert atmosphere of CO₂? (NCERT)
Answer:
When white phosphorus is heated with cone. NaOH solution in an inert atmosphere of CO₂, phosphine gas is prepared.

Question 13.
What happens when PCl₅ is heated? (NCERT)
Answer:
PCl₅ has three equatorial and two axial bonds. Since axial bonds are weaker than equatorial bonds, therefore, when PCl₅ is heated, the less stable axial bond breaks to form PCl₃.

When heated, it sublimes but decomposes on stronger heated.

Question 14.
How are Xenon fluorides XeF₂, XeF₂ and XeF₆ prepared?
Answer:
Xenon Fluorides:
Three fluorides of xenon are important. These are xenon difluoride (XeF₂), xenon tetrafluoride (XeF₄) and xenon hexafluoride (XeF₆).The fluorides of xenon can be prepared by the direct combination between xenon and fluorine under different conditions.

Question 15.
Write the difference between the bleaching action of SO₂ and Cl₂.
Or,
Bleaching of flowers by Cl₂ is permanent while bleaching by SO₂ is temporary, why?
Answer:
Bleaching action of SO₂:
Bleaching by SO₂ is due to the process of reduction in the presence of moisture.
SO₂ + 2H₂O →H₂SO₄ + 2 [H] (nascent)
The nascent hydrogen liberated in the reaction is responsible for bleaching flower but when the flower comes in contact with air. It gets oxidized and become coloured.
Coloured substance + [H] → Colourless \(\underrightarrow { air }\)Colour

Bleaching action of Cl₂:
Bleaching by Cl₂ is due to the process of oxidation in the presence of moisture.
Cl₂ + H₂O → 2HCl + [O ] (nascent)
Coloured substance + [O] > Colourless
The oxygen liberated in the reaction is responsible for bleaching, colour bleached by Cl₂ is permanent and original colour cannot be restored on exposure to air.

Question 16.
Write main differences between the properties of white phosphorus and red pljosfrtiorus. (NCERT)
Answer:
Comparison of properties of White and Red phosphorus :

Question 17.
Give equations for the reaction of chlorine with the following :

1. NH₃
2. NaOH
3. H₂O
4. Bleaching property.

Answer:
Reaction of chlorine :

1. With NH₃ :
(a) Cl₂ reacts with excess of NH₃ and form NH₄Cl and N₂.

(b) When chlorine is taken in excess, an explosive product nitrogen trichloride is formed.
NH₃ +3C₁₂ → NC₁₃ +3HCl

2. With NaOH :
(a) Cold and dilute NaOH reacts with Cl₂ and form chloride and hypochlorite.
Cl₂ + 2NaOH → NaCl + NaClO + H₂O

(b) Hot and concentrated caustic soda reacts with Cl₂ and form chloride and chlorate.
3Cl₂ + 6NaOH → NaC1O₃ + 5NaCl + 3H₂O

3. With H₂O :
Cl₂ reacts with water and form chlorine water which is called hypochlorous acid which decomposes into HCl.

4. Bleaching action:
In presence of moisture chlorine bleaches coloured object and vegetables. It decolourises the coloured substance. This property is due to oxidation.

Thus, bleaching by chlorine is a permanent process.

Question 18.
Give reason :

1. Iodine exhibits some metallic property.
2. Halogens are strongly oxidizing, Why? (MP 2018)

Answer:
1. Ionization energy of iodine is small so it gives out one electron from its valence shell. In some reaction Iodine gives I⁺ ion so it has some metallic property.
I → I⁺ + e^–

2. Halogens are only one electron short to complete their octet and attaining stable structure. So halogens have strong tendency to accept electron. Thus, halogens are strong oxidising agents because of accepting electrons in reduction, oxidising power of halogens decreases from fluorine to iodine.
F₂ > Cl₂ > Br₂ > I₂

The p-Block Elements Long Answer Type Questions

Question 1.
What are interhalogen compounds? How many types are they? Give one example of each type with structure.
Or,
Explain hybridization in ABS and AB? type of interhalogen compounds and draw their structures.
Answer:
Because of difference in the electronegativity value of halogen member it is possible to combine to form compound. When two different halogen combine together to form binary compound, then it is known as interhalogen compound. There are four types of interhalogen compound, which has general formula XY_n, where n = 1, 3, 5 or 7.

Structure of interhalogen compound:
1. AB Type :
Like ClF, BrCl, IBr, ICl. Their geometry is linear. In the ground state electronic configuration of chlorine it is clearly observed that there is one unpaired electron which forms covalent bond with other halogen atom.

2. AB₃ Type :
It is T – shaped. Like ClF₃molecule, Its central atom X shows sp³ hybridization.

3. AB₅ (IF₅ ,BrF₅ )TyPe :
These type of compounds show sp³ d² hybridization. Then structure is square pyramidal in which there is lone pair of electron at one place. Like in the figure formation of IF₅ molecule is shown.

4. AB₇(IF₇) Type :
Its geometry is pentagonal bipyramidal which is formed by sp³d² hybridization. Hybridization in IF7 molecule is sp³d³.

Question 2.
Write the uses of Noble gases.
Answer:
Uses of Noble Gases :
Uses of Helium :

1. It is used in filling air ships and balloons for weather study as it is light and non – inflammable.
2. Helium is used in research work for maintaining very low temperatures.
3. It is used in producing inert atmosphere, for food preservation and as filler in electric transformer.
4. Sea divers use mixture of helium and oxygen for deep sea diving.

This is due to the fact that under high pressure helium is less soluble in blood as compared to nitrogen. If for breathing in deep sea diving air is used then more nitrogen will dissolve in blood under pressure and when the diver comes back at the surface of the sea, the solubility of nitrogen in blood decreases due to decrease in pressure and changes into nitrogen bubbles. This causes severe pain in diver’s body. It may also cause blisters and vomiting.

Uses of Neon:
Neon lights are used for commercial advertisements. It consists of a long tube fitted with electrodes at both ends. On filling the tube with neon gas and passing electric discharge of about 1000 volt potential, a bright red light is produced. Different colours can be obtained by mixing neon with other gases. For producing blue or green light neon is mixed with mercury vapours.

Uses of Argon:

1. Like helium, it is also used to create inert atmosphere in welding of aluminium and stainless steel.
2. It is filled in electric bulbs along with 25% nitrogen.
3. It is also used in radio valves.
4. Argon alone or its mixture with neon is used in tubes for producing lights of different colours.

Uses of Krypton and Xenon:

1. They are also used in electric bulbs in place of argon, but they are costly.
2. Both are used in flash photography.
3. Krypton is mainly used in producing fluorescence, incandescence and electric lights.
4. Krypton lamp is used as indicator at aeroplane terminals for landing of the aeroplane.

Uses of Radon:

1. In treatment of malignant growths (cancer) and non – healing wounds. Also, used in researches associated with radioactivity.
2. Used as a substitute for X – rays in radiology.
3. Radon is soluble in fatty compounds and recently a radon containing ointment has been manufactured for radiotherapy.

Question 3.
Explain manufacture of chlorine under the following heads :
Answer:

1. Labelled diagram of Nelson cell
2. Principle
3. Deacon’s process.

Answer:
1. Nelson cell:
In Nelson cell, graphite anode is suspended in a perforated cylindrical steel cathode provided with asbestos. Brine solution is taken in steel cathode. On electrolysis, chlorine gas is liberated at anode and is drawn off through the outlet at the top. Na reacts with H₂O at bottom to form NaOH and H₂. Hydrogen escapes through the exit.

2. Principle:
Nelson method or By electrolysis:
Chlorine is manufactured by electrolysis of NaCl solution, chlorine is obtained as by product.
NaCl ⇌ Na⁺ + Cl^–

At cathode : 2Na⁺ + 2e^– → 2Na
2Na⁺ + 2H₂O → 2NaOH + H₂

At anode : cl⁺ + e^– → Cl
Cl + Cl → Cl₂

Deacon’s process:
Previously chlorine was manufactured by Deacon’s process. In this process, HCl gas is heated with oxygen at 450°C in presence of CuCl₂ catalyst.

Question 4.
Explain Siemen – Halskey ozonizer processor the manufacture of ozone and draw labelled diagram.
Answer:
For commercial production of ozone Siemen – Halskey ozonizer is used. It consists of an iron box fitted with 6 to 8 glass cylinders. Each cylinder is 3 ft high and 10″ in width. The box is divided into three compartments. Cold water flows through the central compartment for cooling. Each cylinder is fitted with an aluminium rod which are resting on insulating glass slab in the lower compartment.

There is annular space between rod and sides of cylinder. A current of air flows through this annular space. The aluminium rods are subjected to high potential of 8,000 to 10,000 volts. The air which enters at bottom escapes at the top and contains about 5% of ozone. If pure oxygen is used in place of oxygen then ozonized oxygen contains about 15% of ozone.

Question 5.
Explain the structures of XeF₂ and XeF₄.
Answer;
Structure of XeF₂:
In XeF₂ molecule Xe atom is in sp³d hybrid state hence, its structure is trigonal bipyramidal but its geometry is linear.

Structures of XeF₄:
XeF₄ formed under second excited state of Xe where two of sp – orbitals are unpaired and 4 unpaired electron develop. Being sp³d² hybridization involved, the structure is octahedral but due to presence of two lone pair of electron geometry molecules get distorted and becomes square planar.

Question 6.
Dtim labelled diagram of laboratory method of phosphine and give chemical emurfion.
Answer:
Phosphine is prepared in laboratory by heating white phosphorus with NaOH in an inert atmosphere of CO₂ and oil gas. Phosphine produced is highly inflammable due to the presence of phosphorus dehydride as impurity. Vapour of phosphine form vortex noing of smoke in contact with air. Alcoholic KOH can be used in place of NaOH.

Question 7.
Describe Brodie’s Ozonizer with diagram.
Answer:
It is U – shaped glass tube, consists Pt wire with dil. H₂SO₄. The whole apparatus is put into glass utensil, outer utensil also contain H₂SO₄ and Pt electrode. Dry O₂ is passed through U – tube under the influence of high electric discharge oxygen gets converted to ozonised oxygen, the outcoming gas contains 20% of ozone.

Question 8.
Give chemical reaction of ozone with

1. K₂MnO₄
2. I₂
3. Ag₂O
4. CH₂ ≡ CH₂ and (v) PbS.

Answer:
1. With K₂MnO₄ : Potassium permangnate is formed.
2K₂MnO₄ + H₂O + O₃ → 2KMnO₄ + 2KOH + O₂

2. With I₂ : Iodic acid is formed.
I₂ + H₂O + 50₃ → 2HIO₃ + 5O₂

3. With Ag₂O : Silver is formed.
Ag₂O + O₃ → 2Ag + 2O₂

4. With CH₂ = CH₂ : Ethene ozonide is formed.

5. With PbS : PbS04 is formed.
PbS + 4O₃ → PbSO₄ + 4O₂

Question 9.
Explain Ostwald’s process of manufacture of nitric acid drawing labelled diagram.
Answer:

Principle of Ostwald’s process:
The mixture of ammonia and air when passed over platinum gauze catalyst at 750 – 900°C, ammonia gets oxidized to nitric oxide.

The reaction is exothermic and the heat liberated maintains the temperature of the catalyst. The nitric oxide is then oxidised to nitrogen dioxide by air which is cooled to 50°C and absorbed by water to produce nitric acid.

Question 10.
Describe the manufacture of H₂SO₄ by contact process. (NCERT)
Answer:
Manufacture of sulphuric acid:
Sulphuric acid is prepared on large scale by contact process. The basic raw material used is either sulphur or iron pyrites.

Principle of contact process:
When pure and dry SO₂ mixed with air is passed over V₂O₅ catalyst it gets oxidised to SO₃ which is absorbed by H₂SO₄ to form oleum i.e,, H₂S₂O₇.
2SO₂ + O₂ → 2SO₃ + 45.2 cal
SO₃ + H₂SO₄ → H₂S₂O₇

Details of the process are given below :
(a) Sulphur or pyrite burners : SO₂ is produced by burning sulphur or roasting pyrites in pyrite burners.

(b) Purification unit: This unit is an assembly of various parts like.
(i) Dust chamber : SO₂ gas produced is passed through dust chamber through which steam is sprayed from top. Dust particles absorb moisture, become heavy and settle down.

(ii) Cooling pipes : Now, the gaseous mixture is passed through cooling pipes to lower the temperature to 100°C.

(iii) Washing tower or scrubbers : It is filled with quartz and showers of cold water continue from top. Dust particles as well as soluble impurities settle down and are removed.

(iv) Drying tower : It is a high tower full of quartz pieces. Cone. H₂SO₄ is sprayed from the top. Gases enter the tower from bottom and get dried in contact with cone. H₂SO₂.

(v) Arsenic purifier : It is filled with shelves containing freshly prepared ferric hydroxide which absorb the impurities of arsenic purified and dried.

(c) Testing box:
Before sending the gaseous mixture to contact chamber it is tested here. A strong beam of light is thrown into the testing box, if the gaseous mixture contains dust or any other particles they become visible, hence gaseous mixture is repurified. The completely pure gas is then sent to the contact chamber.

(d) Preheater:
Pure gas free from dust particle is heated in preheater to 450°C and then passed into contact tower, where SO₂ gets oxidized to SO₃. This reaction is exothermic due to which temperature of contact tower raises to 450°C. After this the pure gases are pumped directly into the contact tower.

(e) Contact tower:
It consists of a big iron container containing several pipes filled with vanadium pentoxide or platinized asbestos or any other suitable catalyst. Temperature is maintained at 450°C. Pure and dry SO₂ reacts with air in these pipes to form sulphur trioxide.

On account of exothermic nature of reaction, sufficient heat is available.

(f) Absorption tower:
The sulphur trioxide is then passed into a tower in which cone, sulphuric acid flows down in the form of spray. Sulphuric acid absorbs SO₃ and becomes more concentrated. This acid, due to excess of SO₃ produces a fog in the tower. The acid obtained is called fuming sulphuric acid or oleum.

Oleum is mixed with calculated quantity of water to form acid of a particular strength.
H₂S₂O₇ + H₂O → 2H₂SO₄
It may be noted that sulphur trioxide is not directly absorbed in water to form sulphuric acid because it forms a dense fog of sulphuric acid which does not condense easily.

Question 11.
Write formula, structure and oxidation state of any three oxy – acids of chlorine
Answer:

Structure:

Structure of HClO:
The central atom Cl in CIO ion of HCIO, forms four hybrid orbitals by sp3 hybridization. On three orbitals lone pair of electron is present and fourth orbital forms σ – bond by overlapping with d – orbital of oxygen atom. It’s structure is linear.

Structure of HClO₃ :

Structure of HClO₄ :
sp³ hybridization is found in it’s central atom Cl, hence structure of ClO₄ ion is tetrahedral.

MP Board Class 12th Chemistry Important Questions

MP Board Class 12th Chemistry Important Questions Chapter 6 General Principles and Processes of Isolation of Elements

General Principles and Processes of Isolation of Elements Important Questions

General Principles and Processes of Isolation of Elements Objective Type Questions

Question 1.
Choose the correct answer :

Question 1.
In the extraction of Fe from haematite, lime stone acts as :
(a) Reducing agent
(b) Slag
(c) Gange
(d) Flux.
Answer:
(d) Flux.

Question 2.
Cupellation is used in the metallurgy of:
(a) Cu
(b) Ag
(c) Al
(d) Fe.
Answer:
(b) Ag

Question 3.
Which is the essential part of photographic plates and Films :
(a) AgNO₃
(b) Ag₂S₂O₃
(c) AgBr
(d)Ag₂CO₃
Answer:
(c) AgBr

Question 4.
Malachite is :
(a) Cu₂S
(b) CUCO₃.CU(OH)₂
(c) Cu₂O
(d) CuCO₃.
Answer:
(b) CUCO₃.CU(OH)₂

Question 5.
AgBr is soluble in hypo because its forms :
(a) Ag₂SO₃
(b) Ag₂S₂O₃
(c) [Ag(S₂O₃)₃]^–
(d) [Ag(S₂O₃)₂]^3-
Answer:
(c) [Ag(S₂O₃)₃]^–

Question 6.
AgCl is soluble in ammonia due to the formation of:
(a) [Ag(NH₃)₄]⁺
(b) [Ag(NH₃)₃]²⁺
(c) [Ag(NH₃)₄]³⁺
(d) [Ag(NH₃)₂]⁺
Answer:
(d) [Ag(NH₃)₂]⁺

Question 7.
When KI mixed with solution of CuSO₄, it forms :
(a) Cul₂
(b) Cul^2-₂
(c) K₂[CuI₄]
(d) Cu_2& I₂ + I₂
Answer:
(d) Cu_2& I₂ + I₂

Question 8.
When KCN reacts with solution of CuSO₄, it forms :
(a) CU(CN)₂
(b) CuCN
(c) K₂[Cu(CN)₄]
(d) K₃[Cu(CN)₄]
Answer:
(d) K₃[Cu(CN)₄]

Question 9.
Na₂S₂O₃ used in photography as a :
(a) Reducing agent
(b) Developer
(c) Fixer
(d) Toning agent
Answer:
(c) Fixer

Question 10.
Calomel is :
(a) Hg₂ Cl₂
(b) HgCl₂
(c) Hg₂ Cl₂ +Hg
(d) Hg + Hgcl₂
Answer:
(a) Hg₂ Cl₂

Question 11.
German silver is an alloy of :
(a) Cu, Zn and Ni
(b) Cu, Zn and Sn
(c) Ag, Cu and Au
(d) Fe, Cr, Ni
Answer:
(a) Cu, Zn and Ni

Question 12.
Heating pyrites to remove sulphur is called :
(a) Roasting
(b) Liquation
(c) Calcination
(d) Smelting
Answer:
(a) Roasting

Question 13.
Reducing agent in the extraction of Iron from haematite is :
(a) CO
(b) C
(c) CO₂
(d) FeO
Answer:
(a) CO

Question 14.
The Chemical Composition of “Cryolite” mineral is :
(a) Al₂O₃
(b) Al₂O₃.12H₂O
(c) KAl Si₃O₈
(d) Na₃AlF₆
Answer:
(d) Na₃AlF₆

Question 15.
In Photography we use :
(a) Agl
(b) NH₃
(c) AgCl
(d) AgBr
Answer:
(d) AgBr

Question 16.
Blister copper is :
(a) Ore of copper
(b) Alloy of copper
(c) Pure copper
(d) Copper containing 1% empuritis.
Answer:
(d) Copper containing 1% empuritis.

Question 2.
Fill in the blanks :

1. Malachite is an ore of …………………
2. In stainless steel, along with iron ………………… and ………………… metals form alloys.
3.  ………………… is used as a purgative.
4. Colloidal solution of ………………… is used as a medicine of eyes.
5. AgNO₃ is known as …………………
6. Chemical formula of corrosive sublimate is …………………
7. Froath floatation process is generally employed for ………………… ores.
8. The process in which metal oxide is reduced by Al is known as …………………
9. Is used for drying ammonia …………………
10.  ………………… is called lunar caustic.
11. The chemical formula of fluorspar is …………………
12. Alkaline solution of HgCl₂ and Kl is known as …………………
13. Red hot steel is slowly cooled when it gets converted to soft steel, this is known as …………………

Answer:

1. Cu
2. Cr, Ni
3. Calomel
4. Ag
5. Lunar caustic,
6. HgCl₂
7. Sulphide
8. Aluminothermic
9. CuO
10. Silver Nitrate
11. CaF₂
12. Nesseler’s reagent
13. Annealing.

Question 3.
Match the following :
I

Answer:

1. (g)
2. (d)
3. (c)
4. (e)
5. (b)
6. (a)
7. (f)

II.

Answer:

1. (d)
2. (f)
3. (b)
4. (e)
5. (c)
6. (a)

Question 4.
Answer in one word / sentence :

1. The mixture of Cu₂S and FeS obtained from blast furnace is known as.
2. Which metal is purified by polling?
3. After developing which solution is used for the fixing of photographic films? Chemical formula of philosophers’s wool is.
4. Chemical formula of horn silver.
5. Which compound is normally used for toning in photography?
6. Which are known as coinage metals?
7. Give the name of ore used for extraction of Cu.
8. Give the name of ore used for extraction of Iron.
9. What is the name of graph which is drawn between the absolute temperature and standard free energy change for
10. formation of metal oxide?
11. What is the name of iron obtained after the removal of impurities from cast iron?
12. What is the method of slow cooling of hot hard steel known as?
13. What is the method of heating hard steel known as?
14. What is the method of heating steel in pressure of ammonia known as?
15. What is Lunar Caustic?

Answer:

1. Matte
2. Copper
3. Hypo solution (Na₂S₂O₃)
4. ZnO
5. AgCl
6. Aurric chloride
7. Cu, Ag and Au
8. Copperpyrite
9. Haematite
10. Ellinghum diagram
11. Wrought iron
12. Annealing
13. Softening
14. Nitriding
15. AgNO₃

MP Board Class 12th Chemistry Important Questions

MP Board Class 12th Chemistry Important Questions Chapter 5 Surface Chemistry

Surface Chemistry Important Questions

Surface Chemistry Objective Type Questions

Question 1.
Choose the correct answer :

Question 1.
In the adsorption process of acetic acid on activated charcoal, acetic acid is :
(a) Adsorber
(b) Absorber
(c) Adsorbent
(d) Adsorbate.
Answer:
(d) Adsorbate.

Question 2.
Cause of stability of lyophobic sol is :
(a) Brownian movement
(b) Tyndall effect
(c) Electric charge
(d) Brownian movement and Electric charge
Answer:
(d) Brownian movement and Electric charge

Question 3.
In the coagulation of As₂S₃ colloidal solution value of whose coagulating power will be minimum :
(a) NaCl
(b) KCl
(c) BaCl₂
(d) AlCl₃.
Answer:
(d) AlCl₃.

Question 4.
Adsorption process is :
(a) Endothermic
(b) Exothermic
(c) No heat change
(d) None of these.
Answer:
(b) Exothermic

Question 5.
Size of colloidal particles in the range of:
(a) 10^-7 to 10^-9 cm
(b) 10^-9 to 10^-1 cm
(c) 10^-5 to 10^-7 cm
(d) 10^-2 to 10^-8 cm.
Answer:
(c) 10^-5 to 10^-7 cm

Question 6.
Which of the following is not used for the preparation of lyophilic colloid :
(a) Starch
(b) Gum
(c) Gelatin
(d) Metal sulphide.
Answer:
(d) Metal sulphide.

Question 7.
Sol which can act like a protective colloid :
(a) As₂S₃
(b) Gelatin
(c) Au
(d) Fe(OH)₃.
Answer:
(b) Gelatin

Question 8.
Fog is an example of colloidal system of:
(a) Liquid dispersed in gas
(b) Gas dispersed in gas
(c) Solid dispersed in gas
(d) Solid dispersed in liquid.
Answer:
(a) Liquid dispersed in gas

Question 9.
Gelatin is mostly used in making ice creams in order to :
(a) Prevent forming a colloidal sol.
(b) Enrich the fragrance
(c) Prevent crystallization and stabilize the mixture
(d) Modify the taste.
Answer:
(c) Prevent crystallization and stabilize the mixture

(a) Auto catalyst
(b) Poison
(c) Negative catalyst
(d) Positive catalyst.
Answer:
(b) Poison

Question 11.
The migration of colloidal particles under the influence of electric fields is :
(a) Cataphoresis
(b) Electrodialysis
(c) Electrophoresis
(d) Electrical dispersion.
Answer:
(c) Electrophoresis

Question 12.
Hardy – Schulze law is related with :
(a) Solution
(b) Coagulation
(c) Solids
(d) Gases.
Answer:
(b) Coagulation

Question 13.
How many phases are present in a colloidal solution :
(a) 1
(b) 2
(c) 3
(d) 4.
Answer:
(b) 2

Question 14.
Which is an emulsion among the following :
(a) Air
(b)Wood
(c) Butter
Answer:
(d) Milk.

Question 15.
Butter is :
(a) A gel
(b) An emulsion
(c) A sol
(d) Not a form of colloid.
Answer:
(a) A gel

Question 16.
Sol which acts as protective colloid is :
(a) Gelatin
(b) Au
(c) As₂S₃
(d) Fe(OH)₃
Answer:
(a) Gelatin

Question 17.
Which is not correct for physisorption :
(a) A reversible process
(b) Needs low heat of adsorption
(c) Needs activation energy
(d) Needs low temperature.
Answer:
(c) Needs activation energy

Question 18.
In which among the following is Tyndall effect not expected :
(a) Suspension
(b) Emulsion
(c) Sugar solution
(d) Gold sol.
Answer:
(c) Sugar solution

Question 2.
Answer in one word/sentence :

1. Conversion of precipitate into colloidal solution is known as. (MP 2016)
2. Dissociation of emulsion into its constituent liquid is known as.
3. The catalyst which is used for hydrogenation of oils.
4. In dissociation of H₂O₂, phosphoric acts as which type of catalyst?
5. Which catalyst converts glucose into alcohol?
6. Cleansing action of soap based on which principle? (MP 2013)
7. Who used the word catalyst for the first time? (MP 2013)
8. Write the size of colloidal particles.
9. What is the effect of temperature on chemical adsorption?
10. Why does colloidal particle show Tyndall effect? (MP 2013)
11. Movement of particles of colloids is called …………….
12. Give an examples of catalytic poisoning.
13. Colloidal Solution of liquid in liquid is known as …………… (MP 2012 Supply 18)

Answer:

1. Peptization
2. Demulsification
3. Ni
4. Negative
5. Zymase
6. Emulsification
7. Berzellius
8. 10^-5 to 10^-7 cm
9. Increases
10. Scattering of light by colloidal particles
11. As₂O₃ is contect process
12. Brownian movement
13. Emulsion.

Question 3.
Fill in the blanks :

1. Rate of physical adsorption ………………. with the increase in temperature.
2. Particles of As₂O₃ sol are ……………….
3. In the contact process of manufacture of H₂SO₄ for Pt catalyst ………………. act as
4. Oxidation of oxalic acid by KMnO₄ is an example of ……………….
5. Biological catalysts are necessarily ……………….
6. Movement of colloidal particles under the effect of electric field is called ……………….
7. Scattering of light by colloidal particles under the effect of electric field is called ……………….
8. Intermediate compound theory is applicable to ………………. catalyst.
9. The substance on whose surface adsorption takes place is called an ……………….
10. Milk is an example of ……………….
11. Blood is a ………………. charged colloid.
12. Adsorption is an ………………. process.
13. Colloidal solution of solid in liquid is called ……………….
14. Catalytic promoter substance is ……………….
15. On adding electrolyte, precipitation of colloidal particles is known as ……………….
16. According to Hardy Schulze law, coagulating capacity of ions depend on the ………………. of ions.

Answer:

1. Decreases
2. Negatively charged
3. As₂O₃, poison
4. Auto catalysis
5. Enzyme
6. Electrophoresi
7. Tyndall effect
8. Homogeneous
9. Adsorbent
10. Emulsion
11. Negatively
12. Exothermic
13. Gel
14. Molybdenum
15. Coagulation
16. Charge.

Question 4.
Match the following :
I.

Answer:

1. (f)
2. (d)
3. (a)
4. (c)
5. (g)
6. (e)
7. (b)
8. (h).

II.

Answer:

1. (c)
2. (d)
3. (a)
4. (b)
5. (c)

III.

Answer:

1. (e)
2. (d)
3. (a)
4. (b)
5. (c)

Surface Chemistry Very Short Answer Type Questions

Question 1.
Why does physisorption decreases with the increase of temperature? (NCERT)
Answer:
It is an exothermic process
Solid + Gas ⇌ Gas/Solid + Heat
Thus, when temperature is raised, reaction proceeds in backward direction and gas adsorbed gets released. It is accordance to Le – Chatelier’s principle.

Question 2.
Why is it necessary to remove CO when ammonia is obtained by Haber’s process? (NCERT)
Answer:
For the preparation of ammonia in Haber’s process solid catalyst is used. It is necessary to remove the CO produced because the gas reacts with iron and forms Fe(CO)₅ which exist in liquid state at the temperature of the chamber and obstructs in the production of NH₃ because at high temperature CO and H₂ react by which production of ammonia decreases. In short CO acts as poison for the iron catalyst used in the process. It is therefore, necessary to remove CO.

Question 3.
Why is adsorption always exothermic? (NCERT)
Answer:
Adsorption leads to decrease in disorder, thus ∆S = +ve. For the process to be performed value of ∆G should be -ve. Thus, in equation ∆G = AH – T ∆S, ∆G will be negative when ∆H will be negative i.e., exothermic. Thus, adsorption is an exothermic process.

Question 4.
What is adsorbent?
Answer:
Solid substances which adsorb the gases or solution are called adsorbent. Like : animal charcoal, silica etc.

Question 5.
What are adsorbate?
Answer:
Gas molecules, vapours or ions which are adsorbed on the surface of solids are called adsorbate.

Question 6.
Delta is formed when river water meets sea water. Explain.
Answer:
In the river water negatively charged particles of soil and sand are present. When river water meets sea – water, various ions Na⁺, K⁺ or Mg⁺⁺ present in sea water causes coagulation and soil particles etc. are settle down. Thus a delta is formed.

Question 7.
How is rain possible by spraying silver iodide on clouds?
Answer:
Clouds are charged due to colloidal nature. Silver iodide is an electrolyte. Spraying it on clouds lead to coagulation by which it rains.

Question 8.
How is the adsorption of a gas related to its critical temperature?
Answer:
Higher is the critical temperature of a gas, greater is the ease of liquification of gas i.e., larger are the van der Waals’ forces of attraction. Therefore, greater is the adsorption.

Question 9.
What happen when a freshly precipitated Fe(OH)₃ is shaken with little amount of dilute solution of FeCI₃?
Answer:
A reddish brown colloidal solution of Fe(OH)₃ is obtained. This process is called peptization. The Fe⁺³ ions from FeCl₃ are absorbed on the surface of the precipitate and form positively charged colloidal solution.
Fe(OH)₃ + Fe⁺³ → [Fe(OH)₃] Fe⁺³

Question 10.
Why is sky blue in colour?
Answer:
Dust particles present in air forms colloidal solution whose particles shows Tyndall effect and hence sky appears blue in colour.

Question 11.
KMnO₄ decolourises slowly initially and then rapidly when added to oxalic acid. Why?
Answer:
Addition of KMn04 to oxalic acid oxidises it. Mn⁺² ion produced in this reaction acts as autocatalyst and hence decolourisation occur rapidly.
2MnO₄^– + 5C₂O₄^-2 + 16H^– → 2Mn⁺² + 10CO₂ + 8H₂O

Question 12.
How does emulsifier provide stability to emulsion? Write the name of two emulsifiers?
Answer:
For the stability of emulsion, emulsifier is added. Emulsifier forms an interfacial film between the emulsifying medium and the suspended particles. For an oil/water emulsion, protein, gum acts as an emulsifier and for water/oil emulsion salts of fatty acids and heavy metals are the main emulsifier.

Surface Chemistry Short Answer Type Questions

Question 1.
What are emulsions? What are their different types? Give examples of each type. (NCERT)
Answer:
The colloidal system in which dispersed phase and dispersion medium both are liqvid, is called emulsion.

Types of emulsions :
1. Oil in Water type (O/W) : In this type of emulsion small droplets of oil are dispersed in the water or dispersion medium, example Milk, Vanishing cream.

2. Water in Oil (W/O) : In this type of emulsion, small quantity of water is dispersed in the form of droplets in oil (dispersion medium), example Butter, Cod – liver.

Question 2.
What is the difference between multimolecular and macromolecular colloids? Give one example of each. How are associated colloids different from these two types of colloids?
Answer:
1. Multimolecular collodis:
In this type of colloids the colloidal particles consist of aggregates of atoms or small molecules with diameter of less than 1 nm. For example, a gold sol may contain particles of different sizes having several atoms of gold. Similarly sulphur sol contains about one thousand of S₈ molecules. These are held together by van derwaals forces.

2. Macromolecular colloids:
In macromolecular colloids the dispersed particles themselves are big molecules, usually polymers. The molecular masses of these macromolecules range from thousands to millions. Synthetic compounds e.g. polyethylene, polystrene, nylon, rubber etc. are macromolecules. Since these molecules have dimensions comparable to those of colloidal particles, there dispersions are known as macromolecular colloids. Most lyophillic sols are of this category.

3. Associated colloids (Micelles):
There are certain substances which behave as normal, strong electrolytes at low concentration, but exhibit colloidal properties at higher concentrations due to the formation of aggregated particles. These are called Micelles. These substances are also called Associated Colloids. Surface active agents like soaps and detergents are of this class.

Question 3.
Explain, what is observed :

1. when a Deam oi ngnt is passed through a colloidal sol?
2. An electrolyte, NaCI is added to hydrated ferric oxide sol?
3. Electric current is passed through a colloidal sol?

Answer:

1. Scattering of light by colloidal particles takes place and path of the. light becomes visible (Tyndall effect).
2. The positively charged colloidal particles of Fe(OH)₃ get coagulated by the oppositely charged CF ions provided by NaCI.
3. On passing electric current, the colloidal particles move towards the oppositely charged electrode where, they lose their charge and get coagulated. This is electrophoresis process.

Question 4.
What do you understand by protective colloids?
Answer:
Protective colloid:
On adding small quantity of electrolyte, Lyophobic colloids easily coagulated but if some quantity of hydrophillic colloid is added in Lyophobic colloids, it minimize the effect of addition of electrolyte and coagulation is prevented or very slowly coagulated. This process is called protection of colloid. The hydrophillic colloid which is responsible for protection against coagulation is called protective colloid.

Example:
If a small amount of gum, gelatin or starch is added to As₂S₃sol, its coagulation of NaCI solution is prevented. Thus starch, gum or gelatin protects the As₂S₃ sol.

Question 5.
Give the method of preparation of colloidal solution of ferric hydroxide and sulphur in water.
Answer:
1. To prepare sol of ferric hydroxide, FeCl₃ solution is added in the boiling water dropwise with shaking. Excess of FeCl₃ and HCl are separated by electrodialysis and sol is also stablized by this.
FeCl₃ + 3H₃O → Fe(OH)₃ + 3HCl

2. H2S gas is passed in the solution of nitric acid (oxidising agent) and colloidal solution of sulphur is obtained.
2HNO₃ + H₂S → S + 2H₂O + 2NO₂.

Question 6.
What is catalysis? Explain induced catalysis with an example.
Answer:
Catalysis:
A catalyst is a substance which alters the rate of chemical reaction without being used in the reaction and the phenomenon is known as catalysis.

Induced Catalysis:
In induced catalysis, one reaction already taking place, catalyse the other reaction also which does not occur separately.

Example:
Sodium sulphite (Na₂SO₃) oxidise in the atmosphere easily while sodium arsenite (Na₂AsO₃) does not oxidise in atmosphere separately. When (Na₂SO₃) and Na₃AsO₃ both are kept together, both are oxidised.

Question 7.
What is coagulation? Write Hardy – Schulze’s law.
Answer:
Coagulation:
Colloidal particles are either positively charged or negatively charged. It is seen that on adding some oppositely charged ions or electrolyte, which cancels the charge of colloidal particles and these particles aggregate and change into precipitates. Precipitation of colloidal particles by electrolytes is called coagulation.

Hardy – Schulze’s law:
Coagulating power of an ion is governed by this law according to which, “Greater the valency of an ion greater will be its coagulating power.”

Thus, to coagulate negative sol, the coagulating power of different cations are found to be in the order :
Al³⁺ > Ba²⁺ > Na⁺

Similarly, for the coagulation of a positive sol of Fe(OH)3, the coagulating power of different anions is found to be in the order :
PO₄^3- > SO₄^2- > Cl_–

Question 8.
What do you understand by catalytic promoter and catalytic poison? Give an example of each.
Answer:
Catalytic promoter : Chemical substances which are used to increase the activity of the catalyst are known as Catalytic promoter.
Example :

Catalytic poison : Substances which are used to reduce the activity of catalyst are known.

Question 9.
What do you understand by Electro – dialysis?
Answer:
Electro – dialysis:
Particles of true solutions pass through parchment paper or cellophane but sol particles cannot pass through such membranes. In dialysis, the sol filled in a bag of parchment or cellophane is suspended in pure water. This process is very slow and takes a long time for completion. However, it can be quickened under the influence of an electric field and the process is known as Electro – dialysis.

Artificial kidney used in medical science works on the principle of dialysis.

Question 10.
What is homogeneous and heterogeneous catalysis? Explain with example.
Answer:
Homogeneous catalysis:
The chemical reaction in which reactants and cata¬lysts are in same physical state, are example of homogeneous catalysis.
Example : In lead chamber process of manufacturing of sulphuric acid reactant and catalyst NO are in same physical state – gaseous.

Heterogeneous catalysis:
The chemical reactions in which reactants and catalysts are in different physical state, are examples of heterogeneous catalysis.
Example : In Haber process manufacture of Ammonia.

Question 11.
What is ‘Gold number’? Explain with example.
Answer:
Gold Number:
Protective actions of different lyophilic colloids are compared with gold number. Gold number can be defined as:
“Gold number is the number of miligrams of protective colloid (Lyophilic) which on adding prevents the coagulation of 10 ml. standard gold sol by addition of 1 ml. of 10% NaCl solution.” Thus smaller the value of gold number, higher is it’s protecting action. For example, gold number of gelatin and gum arobic are 0.005 and 0.15 respectively. It means gelatin is better protective colloid because it’s only 0 005 mg quantity is required to prevent coagulation if 10 ml Au sol by addition of 1 ml. 10% NaCl.

Question 12.
What is the importance of emulsifying agents in emulsifications?
Answer:
The process of making emulsions is called emulsification. Emulsions are formed when suitable liquids are mixed and shaked, but the emulsions are thus formed are not stable. To make these emulsions stable some other substances are added, which are known as emulsifying agents. Soap, gum, starch etc. act as emulsifying agents. In absence of emulsifying agents, disperse drops of liquid meet each other to distroy emulsion state. It is supposed that emulsifying agents form membrane at interphase of oil and water which checks the union of droplets.

Question 13.
Give reason :

1. Milk turns sour on adding acid to it.
2. Alum is added to purify water.
3. Delta is formed where river water meets sea.

Answer:
1. Milk is an emulsion of fats dispersed in water. Albumin and caesin are emulsifiers. Addition of acid destroys emulsifiers and hence milk gets coagulated.

2. In impure water, soil particles, bacteria and other soluble impurities are dissolved. When alum is added, the Al+3 ion present in alum destroys the negative charge of impure water. Due to neutralization of charge the impurities are coagulated and settle down.

3. In the river water negatively charged particles of soil and sand are present. When river water meets sea – water, various salts present in sea water causes coagulation and soil particles etc. are settle down. Thus a delta is formed.

Question 14.
Explain positive and negative catalysis with example.
Answer:
Positive Catalysis:
When the velocity of any chemical reaction increases with the presence of catalyst, this type of catalysis is called positive catalysis.

Negative Catalysis:
Catalysts when decrease the velocity of chemical reaction are called negative catalysts or retarders and the process is known as negative catalysis.

Question 15.
What is peptization? Explain.
Answer:
Peptization:
Peptization is a good method of preparing colloidal sols from precipitates. A fresh precipitate is taken for the purpose and a suitable reason or peptizing agents are added. These peptizing agents are generally dilute solutions of electrolytes of common ion. Peptization process is opposite of the process of coagulation.

Example:
When fresh precipitate of aluminium hydroxide is boiled with dilute HCl mixed water, colloidal solution of Al(OH)₃ is obtained. When an electrolyte is added to a fresh precipitate then the particles of the electrolyte preferentially adsorbs an ion and due to electrostatic repulsion undergo in colloidal state. On adding electrolyte ferric chloride to ferric hydroxide precipitate, sol of ferric hydroxide is obtained.

Question 16.
Write difference between Lyophilic and Lyophobic colloids. (MP2016)
Answer:
Differences between Lyophilic and Lyophobic colloids :

Question 17.
What is Brownian motion?
Answer:
Continuous and zig – zag motion of colloidal particles is called Brownian motion. Such movement was first observed by Robert Brown in 1827, hence it is called Brownian motion. Brownian movement is due to the unequal collision at between molecules of dispersed phase and colloidal particles. On increase of size of colloidal particles or decrease in temperature the motion becomes slower.
Example:

1. Zig – zag motion of dust particles entering through ventilator is Brownian motion.
2. Lycopodium powder particles move in water due to Brownian motion.

Question 18.
Write difference between Physical adsorption and Chemical adsorption.
Answer:
Differences between Physical adsorption and Chemical adsorption :
Physical adsorption:

• Low value of enthalpy of adsorption (20 – 40 kJ mol^-1)
• This type of adsorption involves weak ‘van der Waals’ forces between adsorbent and adsorbate.
• Usually takes place at low tempera¬ture and decreases with increase in temperature.
• It is reversible in nature.
• The extent of adsorption is approxi-mately related to the case of liquification of the gas.
• Forms multimolecular layers.
• On increasing pressure, adsorption also increases.

Chemical adsorption:

• High value of enthalpy of adsorption (40 – 400kJmol^-1)
• This type of adsorption involves strong forces of attraction due to chemical bond formation.
• Takes place at high temperature.
• It is irreversible.
• No such correlation.
• Forms monomolecular layers.
• No any effect of pressure.

MP Board Class 12th Chemistry Important Questions

MP Board Class 12th Chemistry Important Questions Chapter 4 Chemical Kinetics

Chemical Kinetics Important Questions

Chemical Kinetics Objective Type Questions

Question 1.
Choose the correct answer :

Question 1.
For most of the reactions, the value of temperature coefficient lies in between :
(a) 1 and 3
(b) 2 and 3
(c) 1 and 4
(d) 2 and 4.
Answer:
(b) 2 and 3

Question 2.
For First order reaction value of tm is : (MP 2012 Supp.)
(a) \(\frac { 0.693 }{ { k }_{ 1 } }\)
(b) \(\frac { 2.303 }{ { k }_{ 1 } }\)
(c) \(\frac { 0.303 }{ { k }_{ 1 } }\)
(d) \(\frac {0.693}{t}\)
Answer:
(a) \(\frac { 0.693 }{ { k }_{ 1 } }\)

Question 3.
A first order reaction gets completed to 75% in 32 minutes. How much time would have been required for 50% completion :
(a) 24 minute
(b) 16 minute
(c) 8 minute
(d) 4 minute.
Answer:
(b) 16 minute

Question 4.
Hydrolysis of sucrose to glucose and fructose is :

an example of:
(a) First order reaction
(b) Second order reaction
(c) Third order reaction
(d) Zero order reaction.
Answer:
(a) First order reaction

Question 5.
Plants prepare starch in the process of:
(a) Flash photolysis
(b) Photolysis
(c) Photosynthesis
(d) None of these.
Answer:
(c) Photosynthesis

Question 6.
For first order reaction the specific reaction constant depends upon :
(a) Concentration of reactants
(b) Concentration of products
(c) Time
(d) Temperature.
Answer:
(d) Temperature.

Question 7.
In the reaction between A and B to form C, A represents first order and B represents second order. Rate equation will be written as :
(a) Rate = k [A]²[B]
(b) Rate = k [A] [B]²
(c) Rate = k [A]^1/2[B]
(d) Rate = k [A] [B]^1/2
Answer:
(b) Rate = k [A] [B]²

Question 8.
The rate of chemical reaction depends upon : (MP 2017)
(a) Active mass
(b) Atomic mass
(c) Equivalent weight
(d) Molecular mass.
Answer:
(a) Active mass

Question 9.
Arrhenius equation is :
(a) k = e^-E_aRT
(b) k = \(\frac { { E }_{ a } }{ RT }\)
(c) k = log\(\frac { { E }_{ a } }{ RT }\)
(d) k = Ae^-E_a/RT
Answer:
(d) k = Ae^-E_a/RT

Question 10.
Unit of velocity constant of first order reaction :
(a) mol litre^-1 sec^-1
(b) mol^-1 litre⁺¹ sec^-1
(c) sec^-1
(d) mol litre^-1 sec
Answer:
(c) sec^-1

Question 11.
Unit of velocity constant of zero order reaction :
(a) mol^-1 litre^-1 sec^-1
(b) mol^-1 litre⁺¹ sec^-1
(c) sec^-1
(d) mol litre^-1 sec
Answer:
(a) mol^-1 litre^-1 sec^-1

Question 12.
Rate constant of a reaction increased with the increase of which of the following factor as :
(a) Pressure
(b) Temperature
(c) Concentration of reaction
(d) All of these.
Answer:
(b) Temperature

Question 13.
Factor on which the rate constant of the 1st order reaction does not depend :
(a) Temperature
(b) Catalyst
(c) Activation energy
(d) Concentration of reactant.
Answer:
(d) Concentration of reactant.

Question 14.
Minimum energy required for molecules to react is called :
(a) Potential energy
(b) Kinetic energy
(c) Nuclear energy
(d) Activation energy.
Answer:
(d) Activation energy.

Question 15.
Law of mass action prepared by :
(a) Dalton
(b) Guddberg and Waaje
(c) Hunds and Mulliken
(d) Arrhenius.
Answer:
(b) Guddberg and Waaje

Question 16.
Unit of reaction rate is:
(a) mol litre^-1 sec^-1
(b) mol^-1 litre sec^-1
(c) mol^-1 litre^-1 sec
(d) mol litre sec
Answer:
(a) mol litre^-1 sec^-1

Question 2.
Fill in the blanks :

1. The rate of a reaction does not depends on the concentration of the reacting species, then the reaction is of ……………………
2. Half life period of a radioactive element is 140 days. On taking 1 gm element initially the amount left after 560 days will be ……………………
3. Fast reactions are completed in less than …………………… seconds.
4. Unit of rate constant for third order reaction is ……………………
5. Difference in the minimum and maximum energy state of reactants is called ……………………
6. Reactions which take place by the absorption of radiations are called …………………… (MP 2016)
7. The total number of molecules which participate in a reaction is called ……………………
8. In the mechanism of a reaction, the slowest step is called ……………………

Answer:

1. Zero
2. \(\frac {1}{2}\) gm
3. 10^-9
4. mol^-2 Litre² second^-1
5. Activation energy
6. Photo chemical reaction
7. Molecularity
8. Rate determining step.

Question 3.
Answer in one word / sentence :

1. What is the relation between threshold energy and activation energy?
2. What is the expression of rate constant for first order reaction?
3. Write alternative form of Arrhenius equation.
4. Write an example of zero order reaction.
5. What is Quantum Efficiency?
6. Write the expression of half life period for first order reaction.
7. Explain Threshold energy.

Answer:

7. The Number of photons absorbed minimum amount of energy which the reactant molecules should possess for effective collision.

Chemical Kinetics Very Short Answer Type Questions

Question 1.
What is the effect of rate constant on temperature? How can this effect of temperature be measured quantitatively? (NCERT)
Answer:
Rate of reaction increases with increase in temperature and with 10°C rise in
temperature its value becomes two times. Arrhenius equation expresses the effect of temperature on constant
K = A_e^{-E _/RT}
Where A is frequency factor and Ea is activation energy of the reaction.

Question 2.
The rate of reaction for A + 2B → Product, will be equal to it\(\frac {-d[A]}{dt}\) = k[A] [B]² if B is present in excess amount then what will be the order of reaction?
Answer:
It will be 1^st order of reaction.

Question 3.
Write alternative form of Arrhenius equation.
Answer:

Question 4.
For a zero order reaction t_1/2is proportional to what?
Answer:
Initial concentration of reactant [A].

Question 5.
What is Energy Barrier?
Answer:
The minimum energy achieved by the reactant only after which it can be converted to product is known as energy barrier. Reactant molecules cannot form activated complex till they reach this height (activation energy) and cannot be converted to form product

Question 6.
Explain the rate determining step.
Answer:
Some chemical reactions complete in one or more steps. Rate of reaction is determined by the slowest step which is known as rate determining step.

Question 7.
If unit of rate constant is litre/mole/sec. then what will be the order of reaction?
Answer:
Order of reaction = Second.

Question 8.
Order of a reaction is zero can its molecularity be zero?
Answer:
Molecularity of a reaction is always a whole number. Thus, it cannot be zero.

Question 9.
What is specific reaction rate?
Answer:
Specific reaction rate of a reaction at a given temperature is equal to that rate of a reaction when concentration of each reactant is unity.
Reaction : A_2(g) + B_2(g) → 2AB_g
Rate of reaction ∝ [A₂][B₂]
If [A₂] = [B₂] = 1, then
Rate of reaction = k, where k = Specific reaction rate constant.

Question 10.
When is the average rate of the reaction equal to its instantaneous rate?
Answer:
When value of time interval is nearly zero or when time by infinite form is minute then the average rate of reaction is comparable to its instantaneous rate.

Question 11.
What are pseudo unimolecular reactions?
Answer:
There are some reactions in which molecularity is more than one i.e. two or more molecules are present, but in the chemical reaction concentration of only one reactant molecule is changed and it is only responsible for rate of reaction. Thus, order is one. These reactions are called pseudo unimolecular reactions.
Example:

Above reaction is bimolecular but concentration of water does not affect the rate of reaction, thus, rate of reaction is proportional to the concentration of sucrose only.
Rate = k[C₁₂H₂₂O₁₁]
Thus, inversion of sucrose is a first order reaction. It is known as pseudo unimolecular reaction.

Question 12.
What is temperature coefficient?
Answer:
Generally, rate of any reaction increases due to increase in temperature. On increasing temperature by 10°C, velocity of reaction is increased up to 2 – 3 times. If velocity constant of a reaction is and it is increased to increasing temperature by 10°C, the ratio of these two constant is called temperature coefficient, i.e.,
\(\frac { { k }_{ t+10 } }{ { k }_{ t } }\) ≈ 2 to 3
Thus, at various time the ratio of rate of reaction which differ by 10°C is known as temperature coefficient.

Question 13.
As compared to water, gasoline vaporizes faster. Why?
Answer:
Value of activation energy of vaporization of gasoline is less than the value of activation energy of water.

Chemical Kinetics Short Answer Type Questions

Question 1.
The conversion of molecules x to y follows second order kinetics. If concetration of x is increased to three times how will it affect the rate of formation of y? (NCERT)
Solution:
For the reaction x → y
Rate of reaction (r) = k[x]² …. (1)
If concentration of x is increased three times, now
Rate of reaction (r)¹ = k[3x]² = k[9x² ] …. (2)
Dividing equation (2) by Question (1),
\(\frac { { r }^{ 1 } }{ r }\) = \(\frac { k[9{ x }^{ 2 }] }{ k[{ x }^{ 2 }] }\) = 9
Thus, the rate of reactions will become 9 times.

Question 2.
Write down the expression representing the rate of reaction.
Answer:
Rate of reaction is the rate of change in concentration of reactant or concentration of product in unit time interval.

Unit of rate of reaction depend on the units of concentration and time. If concentration is represented in mole per litre and time in second, then unit of rate of reaction is mol per litre per second. If time is expressed in minute then unit of reaction rate is mole per litre per minute.

Question 3.
What is the meaning of instantaneous rate of reaction?
Answer:
The rate of reaction does not remain constant during the whole time interval because rate of reaction depends upon the concentration of reactants. As the concentration of reactants decreases with time, the rate of reaction also decreases with time.
In order to express the reaction rate as accurately as possible, the instantaneous rate of reaction is expressed. For this the time interval (∆t) is taken as small as possible.
Instantaneous rate of reaction = –[\(\frac {∆A}{∆t}\)_{∆t → o}
= – \(\frac {d[A]}{dt}\)
Where, d [A] is a change in concentration of reactant A.

Question 4.
What do you know about molecularity of any reaction?
Answer:
Molecularity of Reaction:
‘Number of moles of reactant participating in elementary step of chemical reaction is called molecularity of the reaction.’
There are many reactions which proceed through the number of steps and each step being independent is called elementary step. The rate of reaction is determined by slowest step and it is known as rate determining step. Here molecularity can be defined as “Number of molecules/atoms or ions participating in rate determining step is called molecularity.”
Example:
(i) Unimolecular reaction :
O₃ → O₃ + O
(ii) Bimolecular reaction:
NO + O₃ → NO₂ + O₂

Question 5.
Differentiate between molecularity and order of reaction. (MP 2018)
Answer:
Differences between Molecularity and Order of reaction :
Molecularity:

• It is the total number of molecules which participate in the reaction.
• It is a theoretical concept.
• It is always a whole number.
• Its value is never zero.
• It does not provide any information about mechanism of reaction.

Order of reaction:

• It is the number of molecules which participate in reaction and whose concentration is changed.
• Order of reaction is determined by experimentally.
• Fractional values are also possible.
• Zero value is possible.
• It provides information about mechanisms of reaction.

Question 6.
Write any four factors which affects rate of a chemical reaction.
Answer:
The rate of reaction depends upon the following factors:
1. Concentration of reactants:
At constant temperature, the rate of a reaction increases by increasing the concentration of the reactants.

2. Temperature of the system:
If the concentration of the reactants are constant then the rate of reaction increases by increasing temperature. For 10 degree rise of temperature, the reaction rate becomes double or triple.

3. Presence of catalyst:
Positive catalyst increases the rate of reaction and negative catalyst decreases the reaction rate.

4. Nature of the reactants:
Nature of reactants also affect the reaction rate. In any chemical reaction some old bonds are broken and new bonds are formed. Thus, in case of more simple molecules the lesser is the number of bond breaking and the rate of reaction increase whereas in case of complex molecules more bonds are broken and rate decreases.

5. Exposure to radiations:
The rate of some reactions increases due to some special radiations. For example: In the absence of light the reaction between hydrogen and chlorine is slow, but in the presence of light, the reaction proceeds at a faster rate.

Question 7.
How does rate of any reaction depend on temperature? Explain.
Answer:
Generally, rate of any reaction increases due to increase in temperature. On increasing temperature by 10°C, velocity of reaction is increased up to 2 – 3 times. If velocity constant of a reaction is and it is increased to increasing temperature by 10°C, the ratio of these two constant is called temperature coefficient, i.e.,
\(\frac { { k }_{ t+10 } }{ { k }_{ t } }\) ≈ 2 to 3
Arrhenius provide the following relation for showing the effect of temperature on velocity constant.
k = A.e^-E_a

Question 8.
Write a short note on activation energy?
Answer:
According to Arrhenius, any chemical reaction is only possible when reacting molecules are activated with minimum energy which is called threshold energy. Kinetic energy of most of the molecules are less than this minimum energy. The excess energy which is required to activate reactant molecules, is called activation energy.
Activation energy can be determined by the use of Arrhenius equation

Question 9.
Write four differences between Rate of reaction and Rate constant. (MP 2018)
Answer:
Differences between Rate of reaction and Rate constant:
Rate of reaction:

• It is expressed in terms of consumption of reactants or formation of product per unit time.
• It depends on concentration of reactant at particular moment.
• It generally decreases with the progress of reaction.
• Its unit is mol L^-1 cm^-1.

Rate constant:

• It is proportionality constant in differential form in rate law or rate equation.
• It is independent of concentration of reactant.
• It does not depend on the progress of reaction.
• It changes according to order of reaction.

Question 10.
Prove that half – life period is independent of the initial concentration for the firsforder reaction.
Solution:
Half – life period for the reaction is that period in which the initial concentration of reactant is reduced to half.
For first order reaction :

Thus, the half – life period is independent of the initial concentration for the first order reaction.

Question 11.
(i) 2N₂O₅ → 4N02 +02
(ii) H₂ +I₂ → 2HI
Reaction (i) is first order reaction and (ii) is second order reaction. Why?
Answer:
(i) In reaction 2N₂O₅ → 4NO₂ + O₂, when graph is plotted between rate of reaction and then again graph is plotted between rate of reaction and [N₂O₅]², it is shown that in the first graph straight line is obtained i.e.
rate ∝ [N₂O₅]
or rate = k[N₂O₅]
Therefore, 2N₂O₅ → 4NO₂ + O₂ is first order reaction.

(ii) In reaction H₂+I₂ → 2HI when graph is plotted between rate of reaction and (H₂) (I₂), it is seen that straight line is obtained.
Therefore rate ∝ [H₂][I₂]
Hence, this reaction is of 2^nd order reaction.

Question 12.
What do you understand by order of reaction? Give example. (MP 2011,12,16)
Answer:
Order of reaction:
The order of a reaction is defined as the sum of all the powers to which concentration terms in the rate law are raised to express the observecfrate of the reaction. Suppose there is a general reaction,
aA + bB + cC → product
For which the rate law is
Rate = – \(\frac {dx}{dt}\) = k[A]^p[B]^q[C]^r
Then the order of the reaction n = p + q + r, where, p, q and r are the orders with
respect to individual reactants and overall order is the sum of the exponents i.e.,p + q + r.
When n = 1 the reaction is of first order, if n = 2 the reaction is of second order and so on.
For example : Decomposition of ammonium nitrite occurs as follows :
NH₄NO₂ → N₂ +2H₂O
Rate of reaction = – \(\frac {dx}{dt}\) = k [NH₄NO₂]
Thus, order of this reaction will be 1.

Question 13.
Write unit of rate constant k for the zero order, first order and second order reaction (MP 2012)
Answer:

Chemical Kinetics Long Answer Type Questions

Question 1.
Determine the expression for zero order reaction.
Answer:
Reactions in which rate of reaction does not depend on the concentration of the rede tan ts are called zero order reactions. Consider a zero order reaction
A → B
Where, A and B are concentration of reactants and products. Since in this type of reaction, rate of reaction does not depend on the concentration of reactant therefore, rate of change in concentration of reactant remains constant.
Rate of reaction = Constant.
Let initial cone, of reactants be a moles /It and after time‘t’ x moles are converted into product. Then cone, of A after time t will be (a – x) mol /It.
\(\frac {-d[A]}{dt}\) or \(\frac {dx}{dt}\) ∝(a – x)⁰
or \(\frac {dx}{dt}\) = k₀(a – x)(a – x)⁰ … (1)
Where, k₀ is velocity constant of a zero order reaction.
\(\frac {dx}{dt}\) ∝ (a-x)(a – x)⁰ … (2)
dx = k₀dt … (3)
Integrating equation. (2), we get
x = k₀t + c … (4)
Where, c = integration constant
When, t = 0 then x = 0
Substituting it in equation. (4), we get
0 = k₀ x O + C
or C = 0  …(5)
Substituting this in equation. (4), we get
x = k₀t  … (6)
or k₀ = \(\frac {x}{t}\) = … (7)
Thus, equation. (7) is the velocity equation for zero order reaction. Unit of k
k₀ = \(\frac {x}{t}\)
= \(\frac {mole/litre}{second}\) = mole litre^-1 second^-1

Question 2.
Write the Arrhenius equation in the form of equation of straight line. What will be the slope of a graph using this equation? Calculate the activation energy for the decomposition in a decomposition reaction in which the value of slope obtained is – 9920 when log k is plotted against \(\frac {1}{T}\)
Solution:
Arrhenius equation : Arrhenius gave a relation between rate constant of reaction and temperature which is known as Arrhenius equation, i.e.,
k = Ae^-E_a/RT
Where, k = Rate constant of reaction, A = Frequency factor, Ea= Activation energy, R = Gas constant and T = Absolute temperature.

Taking logarithm both sides of above equation, we get
log_e k = – \(\frac { { E }_{ a } }{ RT }\) + log_e A
or log₁₀ k = log₁₀ A – \(\frac { { E }_{ a } }{ 2.303RT }\) .. (i)
This is a straight line equation. If log₁₀ k and \(\frac {1}{T}\) is plotted at different temperatures, a straight line is obtained whose slope = \(\frac { { -E }_{ a } }{ 2.303RT }\) From the graph, value of slope = \(\frac { { E }_{ a } }{ 2.303RT }\) can be calculated and activation energy (E_a ) can be calculated.
Slope = \(\frac { { -E }_{ a } }{ 2.303RT }\) (Activation energy)
Or E_a = Slope x 2.303 x R
Or E_a = – 9920 x 2.303 x (-4.58)
∴ Ea = 104633.5808 calorie per gm molecule

Question 3.
Derive an expression for rate constant of first order reaction.
Answer:
The reaction in which rate of reaction depends upon the concentration of one mole, are called first order reaction.
Let this reaction is
A → product
Suppose intial concentration of A is a gram mole and after t second x mole consumed and remaining concentration is (a – x) gram mole.
So after t time, the rate of reaction will be proportional to (a – x)
\(\frac {dx}{dt}\) ∝(a – x)
or \(\frac {dx}{dt}\) = k (a – x) (k = Velocity constant) … (1)
or \(\frac {dx}{(a – x)}\) = kdt … (2)
on intergating this equation,
∫\(\frac {dx}{(a – x)}\) = ∫ kdt
or -ln(a – x) = kt + c
Where c is intergating constant, …. (3)
If t = 0 then x = 0
Putting the value of c from eqn. (3),
-ln a = c .. (4)
Putting the value of c from eqn. (4), into eqn. (3).
-ln(a – x) = kt – ln a
or ln a – ln (a – x) = kt
ln \(\frac {a}{(a – x)}\) = kt
or k = \(\frac {1}{(t)}\)ln\(\frac {a}{(a – x)}\)
charging the base of log,
k = \(\frac {2.303}{(t)}\) log \(\frac {a}{(a – x)}\)
It is the desired expression for first order of reaction

Chemical Kinetics Numerical Questions

Question 1.
A first order reaction has a rate constant 1.15 x 10^-3 s^-1 How long will 5g of this reactant take to reduce to 3g? (NCERT)
Solution:
According to question,

Applying first order kinetic equation

Question 2.
The rate of the chemical reaction doubles for an increase of 10K in absolute temperature from 298K. Calculate E_a.
Solution:

Question 3.
The reaction between A and B is first order with respect to A and zero order with respect to B. Fill in the blanks in the following table: (NCERT)

Solution:
Given that the reaction between A and B is first order w.r.t. A and zero order w.r.t. B.
Rate = k [A]¹[B]⁰ but [B]⁰ = I.
Rate = k [A]
From experiment I,
2 x 10^-2 = k (0. 1) ⇒ k = 0.2 min^-1
From experiment II,
4 x 10^-2 = 0.2 [A] ⇒[A] = 0.2 min L^-1
From experiment III,
Rate = (0.2) (0.4) = 0 08 mol L^-1 min^-1
From experiment IV,
2 x 10^-2= 0.2 [A] ⇒ [A] = 0.1 mol L^-1.

Question 4.
For a first order reaction, show that time required for 99% completion is twice the time required for the completion of 90% of reaction. (NCERT)
Solution:

If 90% reaction is getting completed

If 99% reaction is getting completed

Dividing equation (1) by equation. (2),

Question 5.
A first order reaction takes 40 min for 30% decomposition. Calculate tm. [CBSE (Delhi) 2013], (NCERT)
Solution:
30% decomposition means that x = 30% of a = 0.30 a
As reaction is of first order

For a first order reaction,

Question 6.
Show that time required for completing 99.9% of a first order reaction is 10 times of its half life period.
Solution:
If initial concentration of reactant is a, then t = ? for x = 0.999 a
We know that for a first order reaction

MP Board Class 12th Chemistry Important Questions

MP Board Class 12th Chemistry Important Questions Chapter 3 Electrochemistry

Electrochemistry Important Questions

Electrochemistry Very Short Answer Type Questions

Question 1.
Can you store copper sulphate solutions in a zinc pot? (NCERT)
Answer:
No, copper sulphate solution cannot be stored in a zinc container because value of standard electrode potential of zinc is less than of copper. Thus, zinc is a stronger reducing agent than copper.
Zn + Cu²⁺ → Zn²⁺ + Cu.
E_cell = F_cathode – F_anode
= 0.34-(-0.76)
= +1.1V.

Question 2.
Why does the conductivity of a solution decrease with dilution? (NCERT)
Answer:
Because number of ions per cm³ decreases.

Question 3.
Explain, how rusting of iron is envisaged as setting up of an electrochemical cell? (NCERT)
Answer:
Formation of carbonic acid takes place on the surface of iron

Question 4.
Arrange the following metals in the order in which they displace each other from the solution of their salts. Al, Cu, Fe, Mg and Zn. (NCERT)
Answer:
A metal with lesser standard potential (more reactive) can displace the other metal from solution of its salts.

Question 5.
Write the definition of Electrochemical cell.
Answer:
System in which chemical energy is converted to electrical energy by oxidation reduction is known as electrochemical cell or voltaic cell.

Question 6.
What is Electrode potential?
Answer:
The potential difference developed between the electrodes and electrolyte of an electrolytic cell is known as Electrode potential.

Question 7.
What is a strong electrolyte ? Write two examples.
Answer:
Electrolyte which completely dissociate in aqueous solution are known as strong electrolyte.
Example : NaCl, KCl, NH₄Cl etc.

Question 8.
What is meant by standard electrode potential?
Answer:
Standard electrode potential (E°) of a half cell is the potential difference when one electrode is dipped in molar solution of its ion at 298 K. If electrode is gaseous the pressure of gas must be one atmosphere. In IUPAC system, reduction potential are known as standard electrode potential.

Question 9.
Write Ohm’s law.
Answer:
According to Ohm’s law, “It states that potential difference across the conductor is directly proportional to the current (I) flowing through it” i.e.,
Mathematically, it can be written as:
I ∝ V
V = IR (R = Resistance, unit = ohm, Q)

Question 10.
What is cell constant?
Answer:
For a conductivity cell, the ratio of distance between two electrodes (l) and area of cross-section of electrode (A) is called as cell constant.
Cell constant = \(\frac {1}{A}\) or x = \(\frac {1}{A}\)
Unit of cell constant = cm^-1

Question 11.
What is galvanization? Explain.
Answer:
Iron is coated with the layer of zinc to protect it from rusting. This process is known as galvanization. The galvanized iron articles keep their lustre due to the coating of invisible protective layer of basic zinc carbonate, (ZnCO₃) or zinc hydroxide (Zn(OH)₂).

Question 12.
Why is it not possible to determine the Electrode potential of a single half cell?
Answer:
Because Electromotive force of two electrodes containing a complete circuit can be measured.

Question 13.
Write the unit of specific conductance.
Answer:
ohm^-1metre^-1= Ω^-1m^-1 = Sm^-1

Question 14.
What is the relation between equivalent conductance and specific conductance?
Answer:
Λ^c_eq = \(\frac {1ooo×k}{c}\)

Electrochemistry Short Answer Type Questions

Question 1.
Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration. (NCERT)
Answer:
Conductivity:
Conductivity of a solution is defined as the conductance of a solution of 1 cm length and having 1 sq. cm as the area of cross-section.

Molar conductivity:
Molar conductivity of a solution at a dilution (V) is the conductance of all the ions produced from one mole of the electrolyte dissolved in V cm³ of the solution when the electrodes are one cm apart and area of cross – section of the electrodes is so large that the whole of the solution is contained between them. It is usually represented by Λ_m.

Variation with concentration:
The conductivity of a solution (Both for strong and weak electrolytes) decreases with decrease in concentration of the electrolyte i.e., on dilution. This is due to the decrease in the number of ions per unit volume of the solution on dilution. The molar conductivity of a solution increase in the decrease in concentration of the electrolyte i.e., on dilution. This is due to the decrease in the number of ions per unit volume of the solution on dilution.

The molar conductivity of a solution increases with decrease in concentration of the electrolyte. This is because both number of ions as well as mobility of ions increases with dilution. When concentration approaches zero, the molar conductivity is known as limiting molar conductivity.

Question 2.
What is salt bridge ? Write its two functions.
Answer:
‘U’ shaped tube filled with KCl or KNO₃ in Agar – Agar solution or gelatin, is known as salt bridge. It connects the two half cell.

Functions:

1. It allows the flow of current by completing the circuit.
2. It maintains the electrical neutrality.

Question 3.
Write difference between Metallic conduction and Electrolytic conduction.
Answer:
Differences between Metallic conduction and Electrolytic conduction:
Metallic conduction:

• Metallic conduction takes place by movement of electrons.
• There is no chemical change.
• There is no transfer of matter.
• In metallic conduction conductivity decreases with increase in temperature.

Electrolytic conduction:

• Electrolytic conduction takes place by movement of ions.
• Due to chemical change decomposition of electrolyte takes place.
• Transfer of matter takes place as ions.
• In electrolytic conduction conductivity
• increases with increase in temperature.

Question 4.
What are the difference between emf (Cell potential) and potential difference:
Answer:
Differences between EMF (Cell potential) and Potential difference
EMF (Cell potential):

• It is the potential difference between the two terminals of the cell when no current is flowing in the circuit, i.e., in an open circuit.
• It is the maximum voltage which can be obtained from a cell.
• It can be measured by potentiaometrie method.
• Work performed by electromotive force is the maximum work done by a cell.
• It is responsible for continuous flow of current in electric circuit.

Potential difference:

• It is the difference of the electrodes potentials of the two electrodes when the cell is sending current through the circuit.
• It is the less than the maximum voltage as it is the difference of electrode potential.
• It can be measured by simple voltmeter also.
• Work performed by potential difference is less than the maximum work done by a cell.
• It is not responsible for the continuous flow of current in circuit.

Question 5.
What is specific conductance? Give its unit.
Answer:
Specific conductivity:
The reciprocal of resistivity is called specific conductivity. It is defined as the conductance between the opposite faces of one centimeter cube of a conductor. It is denoted by K (kappa).
Thus.
K = \(\frac {1}{ρ}\) (∵ ρ = \(\frac {RA}{l}\)
K = \(\frac {1}{R}\) × \(\frac {1}{A}\)
where, R = Resistance, A = Cross – sectional area of electrodes and l = Length between the electrodes.
Unit = K = \(\frac {1}{ohm}\) × \(\frac { cm }{ { cm }^{ 2 } } \) = ohm^-1 cm^-1
S.I. Unit Scnf1 or Ohm^-1 cm^-1.

Question 6.
What is resistivity of any solution?
Answer:
Resistivity:
When current flow in the solution through two electrodes the resistance is proportional to length and inversely proportional to cross – sectional area A.
R ∝\(\frac {l}{A}\)
or R = ρ\(\frac {l}{A}\)
or ρ = R × \(\frac {A}{l}\)
The constant p (rho) is called resistivity or specific resistance.
Unit: If Z is expressed in cm, A in cm² and R in ohm, the unit of resistivity will be
\(\frac { c{ m }^{ 2 }\times ohm }{ { cm } }\) = ohm cm
If l = 1 cm and A = 1 cm² then ρ = R
or Resistivity of any solution is the resistance of 1 cm cube.

Question 7.
What is equivalent conductance?
Answer:
Equivalent conductance:
“Conductance of total ion produced by one gram equivalent of electrolyte in the solution is called equivalent conductance.” It is denoted by Λ_eq.

Question 8.
What is molar conductance?
Answer:
Molar Conductivity:
The molar conductivity of a solution at definite concentration of (or dilution) and temperature is the conductivity of that volume which contains one mole of the solute and is placed between two parallel electrodes 1 cm apart and having sufficient area to hold whole of the solution. It is denoted by Λ_m.
Mathematically,
Λ m=k × V .. (1)
Where, V is the volume in ml in which one gram mole of substance is dissolved.
If M is molarity or m moles are dissolved in 1000 ml.

Question 9.
Define cell constant. Develop a relation between specific conductance and cetfconstant.
Answer:
Cell constant:
In any conductive cell, the distance between two electrodes and surface area of .electrode A are constant. The ratio of l and a is called cell constant i.e.
cell constant = \(\frac { l(cm) }{ a{ ({ cm) }^{ 2 } } }\)
Unit of cell constant is cm^-1 and it is generally expressed by x.

Relation between specific conductance and cell constant:
For a conductor, the resistance R is directly proportional to length R and inversely proportional to area of crosssection of electrolyte.

Question 10.
What are the factors which influence the electrical conductance of electrolytes?
Answer:
The main factor which influence the electrical conductivity are following :
1. Temperature : It influence following interactions.

• Interionic attractions : It depends upon the solute-solute interactions. Which is found between the ions of solute.
• Solvation of ions : It depends upon solute-solvent interactions. It is relation between ions of solute and solvent molecules.
• Viscosity of solvent : It depends upon solvent-solvent interactions. Solvent molecules are related with each other.

With increase in temperature all these three effects decrease and average kinetic energy of ions increases. Thus, with increase of temperature, resistance of solution decreases and hence conductance increases.

2. Nature of electrolyte:
The conductance of solution depends upon the nature of electrolyte. On the basis of conductance measurement electrolytes are classified as strong electrolyte and weak electrolyte. Strong electrolytes have high value of conductance even at higher concentration also.

3. Dilution or concentration:
It is main factor which influence electrical conductance. Effect of dilution or concentration can be studied indivisually in equivalent conductance, specific conductance and molar conductance. But for a general concept of electrical conductance of solution as the concentration is lowered or dilution increases, electrical conductance of whole solution increases.

Question 11.
What is an Electrolytic cell and how does it work?
Answer:
Electrolytic cells:
In these cells electric current is supplied through an external source, as a result of which chemical reactions take place which is called electrolysis like Electrolysis of water, NaCl, Al₂O₂ etc. For example in Solvay trough cell electrode is immersed in sodium chloride solution and electric current is passed due to which NaCl electrolyses. At mercury cathode sodium is released and at anode chlorine is released. Sodium forms amalgam with mercury and is taken out of the cell.

Electrolysis : NaCl → Na⁺ + Cl^–

At cathode : Na⁺ + e^– → Na
Na + Hg → (Na – Hg) Amalgam

At anode : Cl^– – e^– → Cl
Cl + Cl → Cl₂
In electrolytic cell, electricity is supplied through an external source. Thus, positive pole is anode and negative pole is cathode.

Question 12.
What is meant by electromotive force of an electrochemical cell?
Answer:
The difference in electrode potentials of the two electrodes of an electrochemical cell is known as electromotive force or cell potential. It is expressed in volt. Due to difference in potential electric current flows from an electrode of lower potential to an electrode of higher potential. EMF of the cell can be expressed in terms of reduction potential as :

Cell potential = Standard electrode potential of R.H.S. electrode – Standard electrode potential of L.H.S. electrode
Thus, E_cell = E_redn. (right) – E_redn. (left)
E_cell = E_redn.(cathode) – E_redn.(anode)
EMF of a cell is measured by connecting the voltmeter between the two electrodes of a cell. EMF of a cell depend on the concentration of solutions of both half cells and nature of the two electrodes. For example, In Daniel cell, concentration of CuSO₄ and ZnSO₄ solutions in the two half cells is 1M and at 298 K EMF of the cell is 1.10 volt.

Question 13.
What is electrochemical series? Write its application.
or, Write application and characteristics of Electrochemical series.
Answer:
The series in which elements are arranged in increasing order of standard electrode potential is known as electrochemical series.

Applications of Electrochemical Series :

1. Determination of EMF of cell:
EMF of a cell is the difference between standard reduction potential E° of its cathode and anode.
E°_cell = E°_cathode – E°_anode
If e.m.f. is positive, then the cell reaction proceeds in the required direction and if e.m.f of the cell is negative the cell reaction proceeds in the opposite direction.

2. Calculation of Equilibrium constant of cell:
Equilibrium constant k of the cell can be calculated by determining the e.m.f of the cell by the help of Electrochemical series.
Characteristics:

• Metals which are above hydrogen in the series react with acids to produce hydrogen gas.
• This series represents the standard electrode potential elements i.e, tendency to accept electrons. Elements of negative E° possess the tendency to loose electron.
• Elements which come before in the series displace the metals placed below the series, from their salts.
• At the top of the series strongly reducing elements are present because they possess the tendency to loose electrons.
• Example : Li and below strongly oxidizing like F possess the tendency to accept electron.

Question 14.
What do you understand by standard potential of a half cell? How is the standard potential of a half cell determined?
Answer:
Standard electrode potential E° of an electrode (half cell) is that value of potential when all the substances are at one atmospheric pressure and activity of the species present in the form of reactant and product is one unit. Standard electrode potential (E°) is measured by the use of potentiometer.
E°_cell = E°_R – E°_L = E°_{half cell} – E°_ref

Question 15.
Differentiate between Electrochemical cell (Galvanic cell) and Electrolytic cell.
Answer:
Differences between Electrochemical and Electrolytic cells:
Electrochemical cell:

• It is a device to convert chemical energy into electrical energy.
• It consists of two electrodes in different compartments joined by a salt bridge.
• Redox reactions occurring in the cell are spontaneous.
• Free energy decreases with operation of cell, i.e., ∆G <0.
• Useful work is obtained from the cell.
• Anode works as negative and cathode as positive electrodes.
• Electrons released by oxidation process at anode go into external circuit and pass to cathode.
• To set – up this cell, a salt bridge/porous pot is used.

Electrolytic cell:

• It is a device to convert electrical energy into chemical energy.
• Both the electrodes are in same solution.
• Redox reactions occurring in the cell are non – spontaneous.
• Free energy increases with operation of cell, i.e., ∆G >0.
• Work is done on the system.
• Anode is positive and cathode is negative.
• Electrons enter into cathode electrode from external source and leave the cell at anode.
• No salt bridge is used in this cell.

Electrochemistry Long Answer Type Questions

Question 1.
What is standard hydrogen electrode? How is it prepared?
Answer:
Standard hydrogen electrode:
This consists of gas at 1 atmospheric pressure bubbling over a platinum electrode immersed in 1 M HCl at 25°C (298 K) as shown in figure. The platinum electrode is coated with platinum black to increase its surface. The hydrogen electrode thus constructed forms a half cell which on coupling with any other half cell begins to work on the principle of oxidation or reduction. Electrode depending upon the circumstances works both as anode or cathode.

Cell reaction of standard hydrogen electrode (SHE) when it acts as anode is
H_2(g) → 2H²⁺ + 2e^–
It is as represented as
H_2(g)(1 atm) Pt |H3O⁺_aq(1.0M)
When it acts as cathode, the cell reaction is
2H⁺ + 2e^– → H_2(aq)
and it is represented as
H₃O⁺_(aq)(1.0M)|(latm)Pt
Standard hydrogen electrode (SHE) is arbitrarily assigned a potential of zero.

Question 2.
Derive Nernst Equation for single electrode potential.
Answer:
Value of standard electrode potential given in electrochemical series is applicable only when the concentration of electrolyte is 1M and temperature is 298 K. But in electrochemical cells the concentration of electrolyte is not definite and electrode potential depends on concentration and temperature. In such condition single electrode potential can be expressed by Nernst equation.
For a reduction half reaction, Nernst equation can be expressed as follows:

Where, E = Reduction electrode potential
E° = Standard electrode potential (Mⁿ⁺+concentration 1M and at 298 K)
R = Gas constant = 831 JK^-1mol^-1, T = Temperature (in Kelvin) = 298 K
n = Valency of metal ion, F = 1 Faraday (96,500 coulomb)
On substituting the values : E = E°+\(\frac {0.059}{n}\) log₁₀[M⁺] … (2)
Equation (2) is Nemst equation for single electrode potential.

Question 3.
Write the Faraday’s laws of electrolysis.
Answer:
Faraday’s first law of electrolysis:
The law states that, “The mass of any substance deposited or liberated at any electrode is directly proportional to the quantity of electricity passed.”
Thus, if W gm of the substance is deposited on passing Q coulomb of electricity, then W ∝Q or W = ZQ
Where, Z is a constant of proportionality and is called electrochemical equivalent of the substance deposited. If a current of I ampere is passed for t second, then Q = I x t. So that,
W = Z x Q = Z x l x t
Thus, if Q = 1 coulomb, I = 1 ampere and t = 1 second, then W = Z. Hence, electrochemical equivalent of a substance may be defined as, “The mass of the substance deposited when a current of one ampere is passed for one second.”
As one Faraday (96500 C) deposits one gram equivalent of the substance, hence electrbchemical equivalent can be calculated from the equivalent mass.
i.e., Z = \(\frac {Equivalent mass of the substance}{96500}\)

Faraday’s second law of electrolysis:
It states that, “When the same quantity of electricity is passed through solutions of different electrolytes connected in series, the weight of the substances produced at the electrodes are directly proportional to their equivalent mass.”

For example, for CuSO₄ solution and AgNO₃ solution connected in series, if the same quantity of electricity is passed, then

Question 4.
What is rusting of iron? Describe Electrochemical theory of rusting. An^Corrosion : Process by which the layers of undesirable compounds are formed on the surface of a metal on its exposure to atmospheric condition are called corrosion. Rusting of iron is an example of corrosion, chemically it is Fe₂O₃xH₂O.

Electrochemical theory of rusting :
Anode reaction:
On one spot of iron sheet, oxidation takes place and this spot behaves as an anode.
Fe_(s) → Fe²⁺_(aq) + 2e^–; E° = + 0.44 V.
The electrons which are released at this spot travel through the metal and reach another spot on the metal which acts as cathode. These electrons cause the reduction of oxygen in the presence of hydrogen ions (H⁺). H⁺ ions are formed due to decomposition of carbonic acid formed by dissolution of CO₂ in H₂O.
H₂O + CO₂ → H₂CO₃
H₂CO₃ ⇌ 2H₊ +CO₃^2-+

Cathode reaction:
O_2(g) + 4H⁺_(aq) → 2H₂O; E° = 1.23V

Overall reaction:
2Fe_(s) + O_2(g) + 4H⁺_(aq) → 2Fe²⁺ +2H₂O_(l); E°_cell = 1.67V

Fe2Fe²⁺ ion formed travel on the surface of article and react with more oxygen in the presence of H₂O. This results in the formation of ferric oxide.

4Fe²⁺_aq + O_2(g) + 4H₂O_(l) → 2Fe₂O₃ + 8H⁺_aq

Water present causes the hydration of ferric oxide formed.
Fe₂O₃ + XH₂O → Fe₂O₃.xH₂O (rust) Thus, rust is formed.

Question 5.
What is Kohlrausch law? Give its two applications.
Answer:
Kohlrausch in 1875 gave a generalisation known as Kohlrausch’s law, “At infinite dilution when the dissociation of the electrolyte is complete, each ion makes a definite contribution towards molar conductance of the electrolyte irrespective of the nature of the other ion with which it is associated.”
Or
“The value of molar conductance at infinite dilution is given by the sum of the contributions of ions (cation and anion).”
Mathematically,

Where, λ^∞₊ and λ^∞_– are ionic contributions or ionic conductances of cation and anion while v₊ and v_–are the number of cations and anions in the formula unit of electrolyte.

Applications of Kohlrausch’s law:
(i) Calculation of molar conductance at infinite dilution for weak electrolytes :
Molar conductance or equivalent conductance of weak electrolytes cannot be obtained graphically by extrapolation method, since these are feebly ionized. Kohlrausch’s law enables indirect evaluation in such cases. For example, molar conductances of acetic acid can be obtained from the knowledge of molar conductances at infinite dilution of HCl, CH₃COONa and NaCl which are strong electrolytes. From Kohlrausch’s law, it is clear that

(ii) Determination of degree of dissociation:

Question 6.
Draw a labelled diagram of Daniel cell and explain ceLl reaction.
Or, Draw a labelled diagram of electrochemical cell and write cell reaction.
Answer:
Electrochemical cell:
In the redox reactions, the transfer of electrons between oxidizing and reducing agents occurs through wire and thus chemical energy changes into electrical energy. The device on which chemical energy changes into electricaL energy is called electrochemical cell. These are also known as galvanic or voltaic cells. Working of these cells can be understood with the example of Daniel cell.

Daniel çell:
In this cell, Zn rod is dipped in ZnSO₄ solution and Cu rod in copper sulphate solution. Both solutions are connected through KCL salt bridge. When Zn and Cu electrodes are connected by wire and galvanometer, flow of electrons from Zn to Cu occurs. Zinc atoms change into Zn²⁺ and electrons reach at Cu electrode, where Cu²⁺ changes into Cu metal and this copper deposits on electrode.

Electrochemistry Numerical Questions

Question 1.
Calculate the potential of hydrogen electrode in contact with a solution whose pH is 10. (NCERT)
Solution:
If pH of solution is 10 means its [H⁺] ion concentration is 10^-10 M.
Using, E_cell = E°_cell – \(\frac {0.059}{n}\) log\(\frac { 1 }{ [{ H }^{ + }] }\)
Here E°_cell = 0, n =2, [H⁺] = 10^-10
∴E_cell = 0 – \(\frac {0.059}{2}\) log \(\frac { 1 }{ [{10}^{ -10 }] }\) = -0.59V

Question 2.
Calculate the standard cell potentials of galvanic cells in which the following reactions take place : (NCERT)
1. 2Cr_(s) + 3Cd²⁺_(aq) → Cr³⁺_(aq) + 3Cd
2. Fe²⁺_(aq) +Ag⁺_(aq) → Fe³⁺_(aq) + Ag_(s). Calculate the ∆_rG°, and equilibrium constant of the reactions.
Solution:
1. E°_cell = E°_Ecathode – E°_Eanodg
= – 0.40 -(-0.74) = +0.34V
∆G° = -nFE° = -6 x 96500 x 0.34
= -196860J = -196.86kJmol^-1
∆G° =-2.303 RT log K
– 196860 =-2.307 x 8.314 x 298 log K
or log K = 35.5014 or K
= Antilog 34.5014 = 3.19 x 10³⁴

2. E°_cell = E°_Ecathode – E°_Eanodg
= 0.80 – (0.77) = +0.03V
∆G° = -nFE° = -1 x 96500 x 0.03
= -2895Jmol^-1
= – 2-895 kJmol^-1
∆G° = -2-303 RT log K
– 2895 Jmol^-1 = -2.303 x 8.314 x 298 log K or
or K = Antilog of 0.5074 = 3.22.

Question 3.
Using the standard electrode potentials given in Table 3.1 (in your Text-book), predict if the reaction between the following is feasible : (i) Fe³⁺_(aq) and I^–_(aq)
(ii) Ag⁺_(aq) and Cu_s
(iii) Fe³⁺_(aq) and Br^–_(aq)
(iv) Ag_sand Fe³⁺_(aq)
(v) Br_2(aq) and Fe²⁺_(aq). (NCERT)
Answer:
A reaction is feasible if EMF of the cell is ⁺ve.
Cathode : At which reduction occurs.
Anode : At which oxidation occurs.

Question 4.
If specific conductance of 0.02 mol L^-1 KCI solution at 298 K is 2.48 x 10^-2 Ω^-1cm^-1, then calculate its molar conductance.
Solution:
K = 2.48 x 10^-2 cm^-1, C = 0.02 mol L^-1
Λ_m = \(\frac { 1000k }{ { C }_{ m } }\)
= \(\frac { 1000×2.48×{ 10 }^{ -2 } }{ 0.02 }\)
= 124 Scm² mol^-1

Question 5.
What are weak electrolytes? Give one example. Find out molar conductivity of LiBr aqueous solution infinite dilution when joint conductance of Li^-1 ion and Br^-1 ion are 38.7 Scm² mol^-1 and 78.40 Scm² mol^-1 respectively.
Solution:
Weak electrolytes : These are the substances which dissociate only to a small extent.
Examples: CH₃COOH,NH₄OH
Λ_∞ LiBr = Λ_∞ Li⁺ + Λ_∞ Br^–
Given that,
Λ_∞ Li⁺ = 38.7Scm² mol^-1
Λ_∞ Br^– = 78.40 Scm² mol^-1
Λ_∞ LiBr = 38.7 + 78.40
Λ_∞ LiBr = 117.10Scm²mol^-1

Question 6.
What are strong electrolytes? Find out the molar conductivity of aqueous solution of BaCl₂ at infinite dilution when ionic conductance of Ba⁺² ion and Cl^– ion are 127.30 Scm² mol^-1 and 76.34 Scm² mol^-1 respectively.
Solution:
Strong electrolytes : These are substances which dissociate almost completely into ions under all dilutions.
Examples : NaCl,HCl,CH₃COONa
Λ_∞ BaCl₂ = Λ_∞ Ba²⁺ + 2 Λ_∞ Cl^–
Given that,
Λ_∞ = 127.30Scm²⁺mol^-1
Λ_∞ Cl^-1 = 76.34Scm²⁺mol^-1
Λ_∞ BaCl₂ =127.30+2(76.34)
= 127.30 + 152.68
= 279.98 Scm²⁺mol^-1

MP Board Class 12th Chemistry Important Questions

MP Board Class 12th Chemistry Important Questions Chapter 2 Solutions

Solutions Important Questions

Very Short Answer Type Questions

Question 1.
Write formula of van’t Hoff factor ‘i’
Answer:
van’t Hoff factor, i = \(\frac {Observed value of colligative property}{Calculated value of colligative property}\)

Question 2.
Write down van’t Hoff equation. Give formula used for calculating molecular mass with its help.
Answer:
van’t Hoff equation, πV = nRT
or π = \(\frac { nRT}{V}\)
or π = \(\frac { WRT}{MV}\)
or π = \(\frac { WRT}{πV}\)
Where, W is mass of solute, R is Solution constant, T is temperature, n is osmotic pressure and V is volume of Solution.

Question 3.
Define Normality.
Answer:
Number of gram equivalent of solute present in one litre of Solution: is called normality. It is represented by N.
Normality (N) = \(\frac {Number of gram equivalent of solute}{Volume of Solution: in litres}\)
or N = \(\frac {Mass of solute in grams }{Equivalent mass of solute}\) x \(\frac { 1000}{ Volume of Solution: in ml }\)
∵ [No. of gram equivalent =\(\frac {Mass of solute in grams}{Equivalent mass of solute}\)]
Normality of a Solution changes with temperature as it is based on mass – volume relationship and volume changes with change in temperature.

Question 4.
Differentiate between Molarity and Molality.
Answer:
Differences between Molarity and Molality :
Molarity (M):

• Molarity involves the total volume of Solution.
• In molarity, gram moles of solute are dissolved in 1 litre of Solution:.
• Molarity changes with temperature because volume changes with temperature.

Molality (m):

• Molality involves the mass of solvent.
• In molality, gram moles of solute are dissolved in 1 kg of solvent. Here volume of Solution is not considered.
• Molality is independent of temperature as it takes mass into consideration.

Question 5.
Explain the following term : Parts per million.
Answer:
Parts per million:
When a solute is present in very minute amounts (in traces), the concentration is expressed in parts per million abbreviated as ppm. The parts may be of mass or volume. It is the parts of a component per million parts of the Solution.
i.e., ppm = \(\frac {Mass of component A}{Total mass of Solution:}\) x 10⁶
or ppm = \(\frac {Volume of component A}{Total volume of Solution:}\) x 10⁶
Where, ppm. is the concentration of component A in parts per million.

Question 6.
What role does the molecular interaction play in a Solution: of alcohol and water? (NCERT)
Answer:
Alcohols dissolve in water due to formation of inter – molecular H – bonding with water.

Question 7.
Why do gases always tend to be less soluble in liquids as the temperature is raised? (NCERT)
Answer:
Gas + Liquid ⇌ Dissolved gas   ∆ H = – ve
The dissolution of a gas in a liquid is exothermic process. Therefore in accordance with Le – Chatelier’s principle with increase in temperature, the equilibrium shifts in back-ward direction. Therefore, the solubility of gas in Solution decreases with the rise in temperature.

Question 8.
State Henry’s. (NCERT)
Answer:
Henry’s law:
According to this law, ‘The mass of a gas dissolved per unit volume of a solvent at constant temperature, is proportional to the pressure of the gas with which the solvent is in equilibrium’. Let in unit volume of solvent, mass of the gas dissolved is m and equilibrium pressure be P, then m ∝P or m = KP, where K is a constant.

Question 9.
What are colligative properties?
Answer:
The physical properties of Solution which depend on the number of total particles present in Solution and the ratio of number of particles of solute not on the nature of solute particles are known as colligative properties.

Question 10.
Give an example of Solution: of solid in solid.
Answer:
Mixture of copper and gold is an example of solid in solid.

Question 11.
On dissolving ethanoic acid in benzene, experimental molecular mass of ethanoic acid is generally found to be double. Why?
Answer:
On dissolving ethanoic acid in benzene, it dimerizes due to the formation of hydrogen bond. Thus, its experimental value is generally found to be double.

Question 12.
What is vapour pressure? What is the effect of temperature on it?
Answer:
Pressure exerted by the vapours on the surface of a liquid at the state of equilibrium is known as vapour pressure. On increasing the temperature vapour pressure increases.

Question 13.
What type of deviation is represented by acetone and CS₂ Solution?
Answer:
Positive deviation.

Question 14.
Why is CaCl₂ used for clearing off snow from the roads?
Answer:
On adding CaCl₂, freezing point of water decreases. Therefore, CaCl₂ is used for clearing off snow from the roads.

Question 15.
Based on solute – solvent interactions, arrange the following in order of increasing solubility in n – octane and explain :
Cyclohexane, KCl, CH₃OH, CH₃CN.
Answer:
For solubility we know Tike dissolves like’, n – octane is a non – polar solvent, hence non-polar compounds will be more soluble.
KCl < CH₃OH < CH₃CN < Cyclohexane.

Question 16.
What is transition temperature?
Answer:
The temperature at which the nature of solubility changes (i.e., first it increases, then decreases) is known as transition temperature. Solubility of sodium sulphate in water increases upto 32.4, then it starts decreasing. Thus, 32.4°C is the transition temperature of sodium sulphate.

Question 17.
Define molarity and molality. (NCERT)
Answer:
Molarity “is defined as number pf gram mole§ of solute dissolved in a litre of Solution. It is denoted by M.
Molality (M) = \(\frac {Mass of solute in gram per litre}{ Molecular mass of solute}\)

Molality is defined as number of moles of solute present in a kilogram (1000 gram) of solvent. It is denoted by m.
Molality (m) = \(\frac {Mass of solute in kg of solvent}{Gram molecular mass of solute}\)

Solutions Short Answer Type Questions

Question 1.
Write down Raoult’s law.
Answer:
The vapour pressure of a solution containing non – volatile solute is directly pro – portional to the mole fraction of the solute.
Mathematically,
\(\frac { { X }_{ A } }{ { X }_{ A }+{ X }_{ B } } \) = \(\frac { P{ A }^{ 0 } }{ { P }_{ A }+{ P }_{ B } } \)
Where, P⁰_A = Vapour pressure of pure solvent, P_A = Vapour pressure of solvent in solution, X_B = Mole fraction of solute.

Question 2.
What is Azeotropic mixture? They are of how many types? (MP 2018)
Answer:
Azeotropic mixture is the mixture of liquids which boil at one temperature with-out any change in composition. For example, at the composition of 95 6% alcohol and 4.4% water. It form an azeotropic mixture which boils at 78.13°C. Components of this mixture cannot be separated fully by fractional distillation.

They are of two types :
1. Low boiling azeotropic mixture:
Such Solutions which represent positive deviation towards Raoulfs law i.e. their vapour pressure is high thus their boiling point is low are known as low boiling azeotropic mixture.

Example:

• CS₂ + Acetone
• C₂ H₅ OH + n – hexane.

2. High boiling azeotropic mixture:
Such Solutions which represent negative deviation towards Raoult’s law i.e. their vapour pressure is low thus their boiling point is high are known as high boiling azeotropic mixture.

Example:

• Acetone + Chloroform
• Ether + Chloroform.

Question 3.
What are ideal and non – ideal Solutions? Explain with example.
Answer:
Ideal Solutions:
Ideal Solutions are those Solutions in which Raoult’s law can be applied completely for all concentrations of the Solutions and at all temperatures.

Condition for ideal Solutions are following :

1. P_A = P_A⁰ X _A and P_B= P⁰_B X B
2. ∆V_mixing = 0 and
3. ∆H_mixing = 0 and

Example:
C₂H₅Br + C₂H₅Cl, C₆H₆ + C₆H₅CH₃, CCl₄ + SiCl₄etc.

Non – ideal Solutions:
Solutions in which Raoult’s law cannot be applied completely for all concentrations and temperatures are called non – ideal Solutions.
For these Solutions:

1. P_A ≠ P⁰_A X_A and p_B ≠ P⁰_BX_B 
2. ∆V_mixing ≠ 0 and
3. ∆H_mixing ≠ 0 and

Example:
Benzene + Acetone, CHCl₃ + HNO₃ etc.

Question 4.
Establish van’t Hoff Solution: equation. (MP 2018)
Answer:
Osmotic pressure of dilute Solution of a non – volatile solute is proportional to absolute temperature of the Solution at constant concentration. This is known as van’t Hoff law.
π ∝ T .. (1)
Derivation : Osmotic pressure n of a Solution: is directly proportional to a molar concentration.
π ∝ C
By eqn.(l) and eqn.(2) π ∝ C (T is constant) .. (2)
or π = RCT .. (3)
Where, R = Gas constant
or
C = \(\frac {1}{V}\)
π = \(\frac {RT}{V}\) .. (4)
πV = RT .. (5)
This is known as van’t Hoff Ideal Solution equation.

Question 5.
Define the following:

1. Molal elevation boiling point constant.
2. Molal freezing point depression constant. (MP 2018)

Answer:
1. Molal elevation boiling point constant : Molal elevation constant can be defined as “The elevation in boiling point of the Solution in which 1 gm of solute is dissolved in 1000 gm of solvent.”
∴ Elevation in boiling point
∆ T_b ∝ m
∆ T_b = K_bm
m= 1, ∆ T_b = K_b
Where K_b = Molal boiling point elevation constant.

2. Molal freezing point depression constant : Molal depression constant may be defined as “The depression in freezing point for 1 molal Solution: i.e., Solution: in which 1gm mole of solute is dissolved in 1000 gm of solvent.”
∴ Depression in freezing point
∆ T_f ∝ m
∆ T_f = k_f
If m = 1, ∆ T_f = k_f
Where K_f = Molal freezing point depression constant.

Question 6.
What is Raoult’s law? Establish its mathematical expression.
Or,
What is Raoult’s law? How can molar mass of a non – volatile solute be determined with its help?
Answer:
Raoult’s law:
For a Solution in which solute is non – volatile, the Raoulf s law may be stated as following :
“At any constant temperature, vapour pressure of solvent collected above the Solution of non – volatile solute, is directly proportional to the mole fraction of solute.” If a non – volatile solute is added to a volatile solvent, the vapour pressure of the solvent decreases. The vapour pressure of the solvent is directly proportional to its mole fraction. As the solute is non – volatile, the vapour pressure of the Solution (P) will be equal to the vapour pressure of the solvent (PA).
P = P_A ∝ X_A
or P_A=KX_A .. (1)
Where, K = Proportionality constant.
Apply eqn. (1) for pure solvent if X_A= 1 and P_A = P⁰_A
Then, P⁰_A = K x 1 .. (2)
Where, p⁰_A= Vapour pressure of pure solvent.
Putting the value of K from eqn. (2) in eqn. (1),
P_A=P⁰_AX_A .. (3)
Where, X_A is the mole fraction of the solvent in the Solution.
The mole fraction of solute is represented as XB.
So, X_A+X_B=1
or X_A= 1 – X_B .. (4)
From eqns. (3) and (4),
P_A= P⁰_A(1-X_B) = P⁰ – P⁰_AX_B
X_B = \(\frac { { P }_{ A\quad }^{ 0 }-\quad { P }_{ A } }{ { P }_{ A }^{ 0 } } \)
P⁰_A is lowering in vapour pressure and \(\frac { { P }_{ A\quad }^{ 0 }-\quad { P }_{ A } }{ { P }_{ A }^{ 0 } } \) is relative lowering in vapour pressure.

On the basis of equation (5) Raoult’s law can be defined as “The relative lowering in vapour pressure of a Solution containing non – volatile solute is equal to mole fraction of solute”.

Question 7.
Give relation between elevation in boiling point and molecular mass of solute.
Answer:
Relation between elevation in boiling point and molecular mass of solute:
Suppose, W_B gram of non – volatile solute dissolve in WA gram of solvent and the molecular mass of non – volatile solute is M_B gram. Then, molality, m will be

Question 8.
What is van’t Hoff factor? How does it equation?
Answer:
van’t Hoff Equation : van’t Hoff equation

Question 9.
What are constant boiling mixture? Write three differences in Ideal solution and Non – ideal Solutions. (MP 2011,15,16)
Answer:
Constant boiling mixtures or azeotropic mixture. A Solution which distils with out change in composition is called azeotropic mixture.
Differences between Ideal and Non – ideal Solution:

Question 10.
Define the following :

1. Reverse osmosis
2. Isotonic Solution
3. Semi – permeable membrane.

Answer:
1. Reverse osmosis:
It may be noted that if a pressure higher than the osmotic pressure is applied on the Solution the solvent will flow from the Solution into the pure solvent through the SPM. The process is called reverse osmosis.

2. Isotonic Solutions:
The Solution:s which have same osmotic pressure are called as isotonic Solution:s. For example, 0.91% Solution of NaCl called as saline water is isotonic with human blood corpuscles. That is why medicines are mixed with saline water before intravenous injections.

Osmotic pressure is a colligative property and depends on the number of solute particles in a Solution So, the isotonic Solution:s must have same number of solute particles in a given volume of Solution Consequently, the isotonic Solution:s are those which have same molality, if that the solute neither associate nor dissociate in the Solution.

3. Semipermeable membrane:
These are the membrane which allow the movement of the solvent molecules through them. The membrane appear to be continuous sheets or films. But they have very tiny holes or pores which are semimicro in nature. Through the holes, only the molecules of solvent can pass while those of bigger solute molecules cannot pass through.

Solutions Long Answer Type Questions

Question 1.
Write five differences in Solution: having Positive deviation and Negative deviation.
Answer:
Differences between Positive deviation and Negative deviation :

Question 2.
Explain in brief Berkeley and Hartley’s method of osmotic pressure measurement and state its uses.
Answer:
Berkeley and Hartley’s method:
In this method, pressure is applied over the Solution to stop the flow of solvent. This pressure is equivalent to osmotic pressure.
In this method, the apparatus consists of a strong vessel made up of steel in which porous pot is fitted. In the porous pot, copper ferrocyanide semipermeable membrane is deposited. The porous pot is fitted with a capillary tube on one side and a water reservoir on the other side. A piston and pressure gauge are fitted to the steel vessel.

The porous pot and steel vessel are filled with water and Solution respectively. Osmosis takes place and water moves into the steel vessel from the porous pot through the semipermeable membrane. This is shown by fall in water level in the capillary tube. This flow of water is stopped by applying external pressure on the Solution with the help of piston.

This method has the following advantages :

1. It takes comparatively lesser time to determine osmotic pressure.
2. Concentration of Solution: does not change, hence better results are obtained.
3. As high pressure is not exerted over semipermeable membrane, it does not break.
4. High osmotic pressure can be measured.

Question 3.
What is molal freezing point depression constant? Derive the formula to establish relation between molal freezing point depression constant and molecular mass of solute.
Or,
What is molal freezing point depression constant? Show that depression in freezing point is a colligative property. How can molecular mass of solute be determined from depression in freezing point?
Answer:
Molal freezing point depression constant is equal to depression in freezing point of the Solution when 1 gm mole is dissolved in 1000 gm of solvent. It is represented by i.e.,
K_f = \(\frac {depression in freezing point}{Number of moles}\)
or ∆ T_f = K_f x m
As K_f is molal freezing point depression constant, then
∆ T_f ∝m
Where, m = Number of moles dissolved in 1000 gm solvent.
Thus, depression in freezing point is proportional to molality of Solution. Molality is directly proportional to number or molecules of solute substance. Therefore, depression in freezing point is a colligative property.
Calculation of molecular mass of solute:
By determination of depression in freezing point, the Molecular mass of non – volatile solute can be determined.
For a Solution: of non – volatile solute,
∆T_f = K_f x m .. (1)
Let WB gram non – volatile solute is dissolved in w_A gram solvent and molecular mass of solute is M_B.

Question 4.
What is elevation in boiling points? How addition of a non – volatile solute elevates the boiling point of a solvent? Explain it with the help of graph diagram.
Answer:
The vapour pressure of the Solution:
containing a non – volatile solute is always less than that of pure solvent. Therefore, the Solution has to be heated to higher temperature so that its vapour pressure become equal to the atmospheric pressure. Thus, the boiling point of Solution (T_b)is always higher than the boiling point of solvent (T_b⁰). The difference T_b – T_b⁰ is called elevation in boiling point.

If we plot graph between temperature and vapour pressure of a pure solvent and its Solution, then following curve is obtained. Curve AB gives the vapour pressure for the pure solvent and the curve CD gives the vapour pressure of the Solution: at different temperature. At temperature T_b⁰ the vapour pressure of the solvent becomes equal to the atmospheric pressure hence it boils at T_b⁰.

Now, by the addition of non – volatile solute, lowering of vapour pressure of the Solution takes place. And to increase the vapour pressure of the Solution to become equal to atmospheric pressure, the temperature rises. Hence, at T_b the Solution boils. Thus, the boiling point is now elevated from T_b⁰ to T_b. The rise in temperature that results by the addition of a non – volatile solute in a solvent is termed as elevation in boiling point. It is represented by ∆T_b.
So, elevation in boiling point (∆T_b) = T_b – T_b⁰.

Question 5.
What are Non – Ideal Solution? How many types of are they? Explain with giving examples.
Answer:
Non – ideal Solutions:
Solutions in which Raoult’s law cannot be applied completely for all concentrations and temperatures are called non – ideal Solutions.
For these Solutions:

1. P_A ≠ P⁰_A X_A and p_B ≠ P⁰_BX_B,
2. ∆V_mixmg ≠ 0 and
3. ∆H_mixmg ≠ 0 and

Non – ideal Solution are of two types :

1. Solutions showing positive deviations:
For such Solutions the total vapour pressure will be greater than the corresponding vapour pressure according to the Raoult’s law. The boiling point of such Solutions are lowered. Because interactions between the mol-ecules of Solution: is less than the interactions between pure solvents and solutes. Thus the vapour pressure greater than expected. In these type of Solution formed enthalpy and volume increases.
Characteristics:

• P_A > P⁰_A X_A and P_B > P⁰_B X_B
• ∆V_mixlng > 0
• ∆H_mixlng > 0

Example:
Solution of Cyclohexane and Ethanol:
In Ethanol, its molecules are held together by hydrogen bond

On adding cyclohexane, the molecules tend to occupy the space between ethyl alcohol molecules. As a result the attractive forces between alcohol molecules becomes less. Thus, formation of such Solution: is slight increase in vapour pressure, endothermic and an increase in volume.

2. Solutions showing negative deviations:
For such Solutions the total vapour pressure becomes less than expected according to the Raoult’s law. Because interaction between molecules of Solution is greater than interaction between the pure solvent or solute molecules. Thus the vapour pressure of Solution is less. In these type of Solutions formed enthalpy and volume decreases.
Characteristics:

• P_A < P⁰_A X_A and P_B < P⁰_B X_B
• ∆V_mixlng < 0
• ∆H_mixlng < 0

Example:
Solution of Acetone and Chloroform:
When acetone and chloroform are mixed, there are new attractive forces due to intermolecular hydrogen bonding. These force become stronger. Thus the formation of such Solution:s is an exothermic and the vapour pressure of Solution is less and decrease in volume.

Solutions Numerical Questions

Question 1.
Calculate the mass of urea (NH₂ CONH₂ ) required in making 2.5 kg of 0.25 molal aqueous Solution. (NCERT)
Solution:
0.25 molal aqueous Solution means that
Moles of urea = 0.25 mole
Mass of solvent (water) = 1 kg = 1000 g
Molar mass of urea = 14+ 2 +12+ 16 +14+ 2 = 60 g mol^-1
∴ 0 .25 mole of urea = 60 x 0.25 mole = 15 g
Total mass of the Solution = 1000 + 15 g
= 1015 g = 1.015 g
∵ 1.015 kg of Solution contain urea = 15 g
∴ 2.5 kg of Solution will require urea = \(\frac {1.5}{1.015}\) x 2.5 kg = 37 g.

Question 2.
Henry’s law constant for CO₂ in water is 1.67 x 10⁸ Pa at 298 K. Calculate the quantity of CO₂ in 500 ml of soda water when packed under 2.5 atm CO₂ pressure at 298 K. (NCERT)
Solution:
According to Henry’s law,
P = K_HX .. (1)
P = 2.5 atm = 2.5 x 101325 Pa, KH= 1.67 x 10⁸ Pa
Putting these values in equation (1), we get

Question 3.
Calculate the mass of ascorbic acid (Vitamin C, C₆H₈O₆) to be dissolved in 75 g of acetic acid to lower its melting point by 1.5°C. K_fK kg mol^-1. (NCERT)
Solution:
We know that ∆T_f = K_f x \(\frac{\mathrm{W}_{\mathrm{B}} \times 1000}{\mathrm{M}_{\mathrm{B}} \times \mathrm{W}_{\mathrm{A}}}\) .. (1)
Given ∆T_f = 1.5, K_f = 3.9 K kg mol^-1, W_A = 75g, MB (ascorbic acid, C₆H₈O6)
= 6 x 12 + 8 x l + 16 x 6 = 176
Putting, these values in equation (1),
1.5 = 3.9 x \(\frac{\mathrm{W}_{\mathrm{B}} \times 1000}{176 \times 75}\)
W_B = 5.077g.

Question 4.
Calculate the osmotic pressure in pascals exerted by a Solution prepared by dissolving 1.0 g of polymer of molar mass 1,85,000 in 450 ml of water at 37°C. (NCERT)
Solution:
π = CRT
= \(\frac {n}{V}\) RT
Here, number of moles of solute dissolved (n)
= \(\frac {1.0}{185,000}\) mol^-1
= \(\frac {1}{185,000}\) g mol^-1
v = 450mL = 0.450 L
T = 37°C = 37 + 273 = 310 K
R = 8.314 K Pa LK^-1 mol^-1
= 8.314 x 103 Pa LK^-1 mol^-1
Substituting these values we get,

Question 5.
Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in aqueous Solution. What should be the molarity of such a sample of the acid if the density of the Solution is 1.504 g ml^-1? (NCERT)
Solution:
68% nitric acid by mass means that
Mass of nitric acid = 68 g
Mass of Solution = 100 g
Molar mass of HNO₃ = 63 g mol^-1
∴ 68 g HNO₃ = \(\frac {68}{63}\) mole = 1.079 mole
Density of solution = 1.504 g mL^-1
∴ Volume of solution = \(\frac {100}{1.504}\)mL = 66.5 mL = 0 0665 L
Molarity of the solution = \(\frac {Moles of the solute}{Volume of Solution in L}\)
= \(\frac {1.079}{0.0665}\) M = 16.23 M.

Question 6.
Vapour pressure of water at 293 K is 17.535 mm Hg. Calculate the vapour pressure of water at 293K when 25g of glucose is dissolved in 450g of water. (NCERT)
Solution:
\(\frac { { p }^{ 0 }-{ p }^{ 0 } }{ { p }^{ 0 } } \) = X₂ = \(\frac { { W }_{ B }{ M }_{ A } }{ { M }_{ B }{ W }_{ A } } \)
or \(\frac { 17.535-{ P }_{ s } }{ 17.535 }\) = \(\frac { 25×18 }{ 180×450 }\)
or \(\frac { 17.535-{ P }_{ s } }{ 17.535 }\) = 5.56×10^-3
17.535 – p_s = 0.0975
P_s = 17.438 mm Hg.

Question 7.
Henry’s law constant for the molality of methane in benzene at 298 K is 4.27 x 10⁵mm Hg. Calculate the solubility of methane in benzene at 298K under 760 mm Hg. (NCERT)
Solution:
Here, KH = 4.27 x 10⁵ mm, P = 760 mm
Applying Hemy’s law, P = K_HX
\(\mathrm{X}=\frac{\mathrm{P}}{\mathrm{K}_{\mathrm{H}}}=\frac{760}{4 \cdot 27 \times 10^{5}}\) =1.78 x 10^-3
∴ Mole fraction of methane in benzene = 1.78 x 10^-3

Question 8.
Benzene and toluene form ideal solution over the entire range of composition. The vapour pressure of pure benzene and toluene at 300K are 50.71 mm Hg and 32.06 mm Hg respectively. Calculate the mole fraction of benzene in vapour phase if 80 g of benzene is mixed with 100 g of toluene. (NCERT)
Solution:
A → Benzene (C₆H₆); B —> Toluene (C₇H₈)
Number of moles of benzene n_A = \(\frac {80}{78}\)
Number of moles of toluene = n_B = \(\frac {100}{92}\)
X_A = \(\frac { { n }_{ A } }{ { n }_{ A }+{ n }_{ B } } \quad\) = \(\frac {1.026}{1.026+1.087}\) = 0.486
X_B = 1 – X_A = 1 – 0.486 = 0.514
Given P°_A = 50.71 mm Hg and P°_B = 32.06 mm Hg
We know, P = P_A + P_B
= P°_AX_A + P°_AX_B
= (50.71 x 0.486) + (32.06 x 0.514)
= 24.65+ 16.48 = 41-13
Mole fraction of components in vapour phase may be calculated by using Dalton’s law,
P_A = y_A x P
y_A = \(\frac { { P }_{ A } }{ p } \quad \) = \(\frac {24.65}{41.13}\) = 0.60

Question 9.
Determine the osmotic pressure of 5% glucose Solution at 25°C. Molecular mass of glucose = 180, R = 0.0821 litre atmosphere. (MP 2013,16)
Solution:
∴5 gm glucose is dissolved in 100 ml.
∴ 180 gm glucose will be dissolved in \(\frac {100}{5}\) x 180
= 3600 ml = 3.6 litre.
We know that,
PV = RT
P x 3.6 = 0.0821 x (25 + 273) = 298
or P = \(\frac {0.52×12.5×1000}{0.63×170}\)
= 6.80 atmospheres.

Question 10.
12.5 gm of urea dissolved in 170 gm of water. The elevation in boiling point was found to be 0.63 K. If KA for water = 0.52 Km^–1, calculate the molecular mass of urea. (MP 2010)
Solution:
Formula: M_B\(\frac { { K }_{ b }x{ W }_{ B }x1000 }{ ∆{ T }_{ b }x{ W }_{ A } }\)
Given: W_A = 170gm,W_B= 12.5gm, ∆T_B=0.63K, K_b=0.52Km^-1
M_B = \(\frac {0.52×12.5×1000}{0.63×170}\)
M_B = 60.7 gm mol^-1

Question 11.
If 6.84 gram sucrose is dissolved in 100 ml. Solution then what will be its osmotic pressure at 20°C? (R = 0.082 litre atmosphere K^-1mol^-1) (Molecular mass of sucrose M_B = 342)
Solution:
Given : Weight of solute (W_B) = 6.84 gm
Molecular mass of solute (M_B) = 342
Volume of Solution: (V) =\(\frac {100}{1000}\) =0.1 litre
Temperature (T) = 20° C = 273 + 20 = 293 K
Solution constant R = 0.082 litre atmosphere K^-1 mol^-1
Osmotic pressure π = \(\frac { { W }_{ B }RT }{ { M }_{ B }V } \)
= \(\frac {6.84×0.082×293}{342×0.1}\)
= 4.8 atmosphere.

MP Board Class 12th Chemistry Important Questions

MP Board Class 12th Chemistry Important Questions Chapter 1 The Solid State

The Solid State Important Questions

The Solid State Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
Due to Frankel defect, density of ionic solids :
(a) Decreases
(b) Increases
(c) Does not change
(d) It changes.
Answer:
(c) Does not change

Question 2.
In CsCl each Cl is surrounded by how many Cs :
(a) 8
(b) 6
(c) 4
(d) 2.
Answer:
(a) 8

Question 3.
Frenkel defect is not shown by :
(a) AgBr
(b) AgCl
(c) KBr
(d) ZnS.
Answer:
(c) KBr

Question 4.
In NaCl crystal number of oppositely charged ions situated at equal distance are:
(a) 8
(b) 6
(c) 4
(d) 2
Answer:
(b) 6

Question 5.
Best conductor of electricity is :
(a) Diamond
(b) Graphite
(c) Silicon
(d) Carbon (non – crystalline).
Answer:
(b) Graphite

Question 6.
Which type of point defect is found in NaCI crystal of KCl crystal: (MP 2009 Set D)
(a) Frenkel defect
(b) Schottky defect
(c) Lattice defect
(d) Impurity defect.
Answer:
(b) Schottky defect

Question 7.
How many space lattices (Bravais lattice) can be obtained from various crystal systems :
(a) 7
(b) 14
(c) 32
(d) 230.
Answer:
(b) 14

Question 8.
Diamond is a :
(a) H – bond solid
(b) Ionic solid
(c) Covalent solid
(d) Glass
Answer:
(c) Covalent solid

Question 9.
The Co – ordination number of Ca²⁺ ions in fluoride structure is :
(a) 4
(b) 6
(c) 8
(d) 3.
Answer:
(c) 8

Question 10.
8 : 8 Co – ordination number is found in which compound :
(a) MgO
(b) A1203
(C) CsCl
(d) All of these
Answer:
(C) CsCl

Question 11.
Co – ordination number of body centred cubic cell is :
(a) 8
(b) 12
(c) 6
(d) 4
Answer:
(a) 8

Question 12.
Density of unit cell is :
(a) \(\frac { ZM }{ { a }^{ 3 }{ N }_{ 0 } } \)
(b) \(\frac { Z{ N }_{ 0 } }{ { a }^{ 3 }M } \)
(c) \(\frac { { N }_{ 0\quad }{ a }^{ 3 } }{ Z } \)
(d) \(\frac { Z }{ M{ N }_{ 0 } } \)
Answer:
(a) \(\frac { ZM }{ { a }^{ 3 }{ N }_{ 0 } } \)

Question 13.
The number of tetrahedral voids in unit cell of cubic close packing :
(a) 4
(b) 8
(c) 6
(d) 2
Answer:
(b) 8

Question 14.
Intra – ionic distance of CsCl will be :
(a) a
(b) \(\frac {a}{2}\)
(c) \(\frac { \sqrt { 3 } a }{ 2 } \)
(d) \(\frac { 2a }{ \sqrt { 3 } } \)
Answer:
(c) \(\frac { \sqrt { 3 } a }{ 2 } \)

Question 15.
Number of atoms in a body centred cubic unit cell is : (MP 2011)
(a) 1
(b) 2
(c) 3
(d) 4.
Answer:
(b) 2

Question 16
Which of the following is Bragg equation :
(a) nλ = 2ϕ sinθ
(b) nλ = 2d sinθ
(c) nλ = sinθ
(d) n\(\frac {θ}{2}\) = \(\frac {d}{2}\) sinθ.
Answer:
(b) nλ = 2d sinθ

Question 17.
Constituents of covalent crystal is :
(a) Atom
(b) Molecule
(c) Ion
(d) All of these.
Answer:
(a) Atom

Question 18.
Number of Na atom present in the unit cell of NaCI crystal is : (MP 2012)
(a) 1
(b) 2
(c) 3
(d) 4.
Answer:
(d) 4.

Question 19.
What type of magnetic substance are Fe, Co, Ni: (MP 2012,18)
(a) Paramagnetic
(b) Ferromagnetic
(c) Diamagnetic
(d) Antiferromagnetic.
Answer:
(b) Ferromagnetic

Question 20.
The correct example of Frenkel defect is : (MP 2012)
(a) NaCI
(b) CsCl
(c) KCl
(d) AgCl.
Answer:
(d) AgCl.

Question 21.
Dry ice (solid CO₂) is a/an : (MP 2012)
(a) Ionic crystal
(b) Covalent crystal
(c) Molecular crystal
(d) Metallic crystal.
Answer:
(c) Molecular crystal

Question 22.
Co – ordination number of Cs in CsCl: (MP2015)
(a) Like Cl i.e., 8
(b) Unlike Cl i.e., 6
(c) Unlike Cl i.e., 8
(d) Like Cl i.e., 6.
Answer:
(a) Like Cl i.e., 8

Question 23.
Structure of NaCI crystal: (MP 2015)
(a) Tetragonal
(b) Cubic
(c) Orthorhombic
(d) Monoclinic.
Answer:
(b) Cubic

Question 24.
Each Na⁺ion in NaCI crystal is surrounded by :
(a) Three Cl^– ions
(b) Eight Cl^– ions
(c) Four Cl^– ions
(d) Six Cl^– ions.
Answer:
(d) Six Cl^– ions.

Question 25.
For increasing of electro conductivity in a solid crystal, mixing of impurities is known as : (MP2016)
(a) Schottky defect
(b) Frenkel defect
(c) Doping
(d) Electronic defect.
Answer:
(c) Doping

Question 26.
Which type of lattice is found in KCl crystal:
(a) Face centred cubic
(b) Body centred cubic
(c) Simple cubic
(d) Simple tetragonal.
Answer:
(a) Face centred cubic

Question 27.
Number of atoms in a body centred cubic unit cell of a monoatomic substance is :
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(b) 2

Question 28.
Radius ratio limit for tetrahedral symmetry is :
(a) 0155
(b) 0.414
(c) 0.732
(d) 0.225
Answer:
(d) 0.225

Question 29.
The defect produced due to a cation and an anion vacancy in a crystal lattice is known as :
(a) Schottky defect
(b) Frenkel defect
(c) Crystal defect
(d) Ionic defect
Answer:
(a) Schottky defect

Question 30.
If co – ordination number of Cs⁺ is 8 in CsCl then co – ordination number of Cl^– ion is :
(a) 8
(b) 4
(c) 6
(d) 12
Answer:
(a) 8

Question 2.
Answer in one word / sentence :

1. Give two examples of metallic crystal.
2. Give two examples of covalent crystal.
3. Give two examples of ionic crystal.
4. What is the co – ordination number of F⁺ ion in CaF₁?
5. What is the value of co – ordination number of hexagonal close packing structure?
6. What is the type of structure of NaCl crystal?
7. Give an example of body centred cubic cell.
8. Give an example of a compound which has both Schottky and Frenkel type of defect.
9. What types of crystal is SiC? (MP 2011)
10. Write Bragg equation. (MP2017)
11. What is effect on the density of a substance or crystal due to Schottky defect?
12. Write the formula of radius ratio.
13. Give two examples of amorphous or non – crystalline solid.
14. F – centres give colour of crystal due to whose presence? (MP 2018)

Answer:

1. Copper, Nickel
2. Diamond, Graphite
3. NaCl, NaNO₃
4. 4
5. 12
6. Cubic
7. CsCl
8. AgBr
9. Covalent solid
10. nλ = 2d sinθ
11. Due to Schottky defect density of substance decreases
12. Radius ratio = \(\frac { radiusofcation\quad { r }^{ + } }{ radiusofanion\quad { r- } } \)
13. Glass, plastic
14. Due to presence of free electron.

Question 3.
Fill in the blanks :

1. The defect produced due to removal of a cation and an anion from a crystal lattice is called …………………. (MP 2018)
2. If in a crystal lattice a cation leaves its lattice site and occupies a space in the interstitial site then the defect is called ………………….
3. The cause of electric conduction of NaCl in its molten state are its ………………….
4. Due to …………………. defect the density of crystal decreases
5. Total …………………. types of crystal system are there.
6.  …………………. proposed the concept of atom for the first time.
7. The ratio of the cation and anion present in a crystal is known as ………………….
8. The process of adding small amount of impurities in an element or compound is called …………………. (MP 2018)
9. Total 14 types of unit cells are there which are known as ………………….
10. In NaCl crystal structure, co – ordination number of both Na⁺and Cl^– ion is ………………….
11.  …………………. defect is found in ZnS and AgCl crystal.
12. Due to Schottky defect, density of crystal ………………….
13. In metallic solids, conductivity is due to the presence of ………………….
14. Point defects are found in …………………. crystals.
15. Substances which are attracted in magnetic field are called ………………….
16. For a unit cell, if r = \(\frac { a }{ \sqrt { 8 } } \), then it will be …………………. type of unit cell.
17. Conductivity of semiconductor …………………. on increasing temperature.

Answer:

1. Schottky defect
2. Frenkel defect
3. Free ions
4. Schottky
5. Seven
6. Kannad
7. Radius ratio
8. Doping
9. Bravais lattice
10. Six
11. Frenkel
12. Decreases
13. Free electron
14. Ionic
15. Paramagnetic substance
16. Fcc
17. Increases.

Question 4.
Match the following:
I. (MP2014)

Answer:

1. (b)
2. (d)
3. (c)
4. (a)

II.

Answer:

1. (c)
2. (d)
3. (a)
4. (b)

III.

Answer:

1. (d)
2. (c)
3. (b)
4. (a)

IV. (MP2017)

Answer:

1. (c)
2. (d)
3. (a)
4. (b)

MP Board Class 12th Chemistry Important Questions

MP Board Class 12th Economics Important Questions Unit 10 Balance of Payments

Balance of Payments Important Questions

Balance of Payments Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
Structure of balance of payment includes which account:
(a) Current account
(b) Capital account
(c) Both (a) and (b)
(d) None of these.
Answer:
(c) Both (a) and (b)

Question 2.
Balance of trade means :
(a) Capital transactions
(b)Import and export of goods,
(c) Total credit and debit
(d) All of the above.
Answer:
(b)Import and export of goods,

Question 3.
Measures to improve adverse balance of payment includes :
(a) Currency devaluation
(b) Import substitution
(c) Exchange control
(d) All of the above.
Answer:
(d) All of the above.

Question 4.
Foreign Exchange Rate is determined by :
(a) Demand of foreign currency
(b) Supply of foreign currency
(c) Demand and supply in foreign exchange market
(d) None of these.
Answer:
(c) Demand and supply in foreign exchange market

Question 5.
Types of Foreign Exchange Market are :
(a) Spot market
(b) Forward market
(c) Both (a) and (b)
(d) None of these.
Answer:
(c) Both (a) and (b)

Question 2.
Fill in the blanks:

1. Bretton woods system is also known as ………………… border system.
2. There is ………………… relation between foreign exchange rate and the supply of foreign exchange.
3. By devaluation, the value of currency …………………
4.  ………………… items are included in the balance of trade.
5. Balance of payment always remains …………………
6. The value of currency of one country with that of the currency of another country is called …………………

Answer:

1. Adaptable
2. Direct
3. Reduces
4. Visible
5. Balanced
6. Exchange rate.

Question 3.
State true or false :

1. Balance of trade includes both visible and invisible items.
2. Balance of trade is a part of Balance of payments.
3. Devaluation is declared by the government.
4. Balance of payment is always balanced.
5. For export promotion, help of devaluation is taken.
6. The increasing population in developing countries has direct impact on economic growth.
7. Export promotion is one of the ways of correcting Balance of payments.

Answer:

1. False
2. True
3. True
4. True
5. True
6. False
7. False.

Question 4.
Match the following :

Answer:

1. (b)
2. (c)
3. (a)
4. (e)
5. (d)

Question 5.
Answer the following one word/ sentence:

1. New trade policy was declared in which year?
2. What will be the effect of devaluation of Indian currency on Indian imports?
3. In the long run, for what do the importers pay?
4. What does capital account imply?
5. What is the exchange of currency of one country in currency of another country called?

Answer:

1. 1991
2. Costly
3. Exports
4. International exchange and Indebtness
5. Ex – change Rate.

Balance of Payments Very Short Answer Type Questions

Question 1.
What is Balance of Payment?
Answer:
The balance of payment of a nation consists of the payments made, within a particular period of time between the residents of the country and the residents of foreign countries.

Question 2.
What do you mean by foreign exchange rate?
Answer:
Meaning:
The rate at which one currency buys or exchanges another currency is known as the rate of exchange. It simply expresses its external value or purchasing power. Foreign exchange rate between the currency units of two countries means the number of units of one national currency that are needed to buy one unit of other national currency.

Question 3.
Differentiate between Balance of Trade and Balance of Payment.
Answer:
Difference between Balance of Trade and Balance of Payment:
Balance of Trade:
The difference between exports and imports is called balance of trade.

Balance of Payment:
The difference between the total receipts of foreign exchange and total payment of foreign exchange is called balance of payment.

Question 4.
What do you mean by unfavourable balance of payment? Explain.
Answer:
Unfavourable balance of payment:
It is also called the deficit balance of payment. It refers to the situation when the total liability for payments of a nation exceeds the total receipts from foreign countries. Hence certain additional transactions are necessary to balance it such as export of gold, withdrawal of deposits in foreign banks etc.

Question 5.
What do you mean by capital account?
Answer:
Capital account is that account of balance of payment which records all such transactions between the residents of a country and rest of the world which cause a change in asset or liability of the country.

Question 6.
What do you mean by current account of balance of payment?
Answer:
Current account is that account of balance of payment which records imports and exports of goods and services and unilateral transfers. It includes visible, invisible and unilateral transfers.

Question 7.
What do you mean by managed floating system?
Answer:
Managed floating system is a mixture of flexible exchange rate system and fixed rate system. (The float part + managed part). Under this system the central bank tend to intervene to buy and sell foreign currencies in an attempt to reduce fluctuation in exchange rate.

Question 8.
What do you mean by protection?
Answer:
When by ending the freedom of foreign trade the ban is put on import and export of goods it is called protection.

Question 9.
Write one advantage of open economy?
Answer:
Investors get the choice of selection among domestic products and foreign goods.

Question 10.
What do you mean by dumping?
Answer:
When the goods are excess than demand then the seller sells this goods in foreign countries on lower rate it is called dumping.

Question 11.
Write points in favour of fixed exchange rate.
Answer:

1. To encourage international trade.
2. Formation of capital.
3. Encouragement to foreign capital
4. Encouragement to export countries.

Question 12.
What do you mean by foreign trade multiplier?
Answer:
Foreign exchange rate multiplier tells us how many times increase takes place in national income by increasing in export.

Question 13.
What does a balance of payment record?
Answer:
The balance of payment records the transaction in goods and services and assets between residents of a country with the rest of the world.

Question 14.
What is dirty floating?
Answer:
When managed floating in the absence of rules and guidelines are implemented, it is called dirty managed floating system.

Question 15.
What do you mean by import and export?
Answer:
Import:
When goods and services are brought from the foreign countries to the domestic countries it is called import.

Export:
Goods and services are send to foreign countries from domestic countries.

Question 16.
What does foreign exchange market include?
Answer:
Foreign exchange market includes banks specialised foreign exchange dealers, brokers, government agencies through which the currency of one country can be exchanged for that of other country.

Question 17.
What do you mean by flexible exchange rate?
Answer:
Flexible rate of exchange:
It is freely determined by the prices of supply and demand in the internal market.

Question 18.
What do you understand by managed floating rate system?
Answer:
It is a hybrid of a fixed exchange rate and flexible exchange rate system. In this system, central bank intervenes in the foreign exchange market to restrict the fluctuations in the exchange rate within certain limits. The aim is to keep exchange rate close to desired target values.

Question 19.
Give arguments in favour of fixed exchange rate.
Answer:
Following points can be studied in favour of fixed exchange rate:

1. Encouragement to international trade.
2. Encouragement to foreign capital.
3. Capital formation.

Question 20.
Write points against fixed exchange rate.
Answer:
Following are the points against fixed exchange rate :

1. Controlled economy.
2. Encouragement to corruption.
3. Sudden change in exchange rate.
4. Unfavourable effect on economic development.

Question 21.
Explain two merits and two demerits of fixed foreign exchange rate.
Answer:
(a) Two merits of fixed foreign exchange rate :

1. Fixed foreign exchange rate ensures stability in exchange rate. The exporters and importers do not have to operate under uncertainty about the exchange rate. Thus, it promotes foreign trade.
2. It also promotes capital movements.

(b) Two demerits of fixed foreign exchange rate :

1. Under this system, countries with deficit in balance of payment run down the stock of gold and foreign currencies. This can create serious problem for them.
2. There may be undervaluation of currency.

Question 22.
Write down the advantages of fixed exchange rate system.
Answer:
Advantages of fixed exchange rate system :

1. This system ensures stability in the international money market/ exchange market.
2. It encourages international trade.
3. It promotes bilateral trade agreements.
4. It avoids speculation.
5. It keeps the government under pressure to combat inflation.

Balance of Payments Short Answer Type Questions

Question 1.
What do you mean by fixed exchange rate? Write three points against it.
Answer:
A fixed exchange rate is a regime applied by a country whereby the government or central bank ties the official exchange rate to another country’s currency or the price of gold. The purpose of a fixed exchange rate system is to keep a currency’s value within a narrow band.

Following are the different points against the fixed exchange rate:
1. Controlled economic system:
For fixed rate of exchange it is compulsory to have strict control over economic system. If it is not possible then we will have to make changes in exchange rate.

2. Unfavourable effect on economic progress :
The main aim of fixed rate of exchange is to maintain stability in exchange rate. In this situation sometimes national income, employment policy, price level etc. are considered as secondary.

3. Corruption:
To maintain fixed exchange rate many restrictions are imposed in the country. Due to strict restrictions there is always possibility of corruption in the society.

4. Sudden change in the exchange rate:
Some times it becomes evitable to make changes in exchange rate. To keep the exchange rate stable some times currency of the nation becomes weak. In such stuation sometimes the there is devaluation. It has adverse effect on foreign trade and balance of payment.

Question 2.
What is meant by flexible exchange rate? Give arguments in favour and against flexible exchange rate.
Answer:
A system in which rate of exchange is determined by the sources of demand and supply of different currencies in foreign exchange market.

Following points which can be studied in favour of flexible exchange rate :

1. Independent economic policy : If the exchange rates are elastic any country can make their domestic economic policies internal policies) independently.

2. Implementation of monetary policy independently : If the rate of exchange is flexible monetary policy in the nation can be independently and effectively by changing the monetary policy.

Following points which can be studied against the flexible exchange rate :

1. Adverse economic effect:
If the flexible exchange rate is there then the feeling of insecurity comes in the minds of traders. It has an adverse effect on the foreign trade of the country. The tendency of gambling increases. If the exchange rate is reduced the inflation increases. The level of employment opportunities also go down.

2. Misuse of the resouroes:
If exchange rate goes on changing very often then the resources have to distributed again and again sometimes the resources are used in export sometimes for domestic industries. Due to these changes there is always wastage of resources.

Question 3.
What do you mean by balance of payment? What are the causes of adverse balance payment in India?
Or
Explain four causes of adverse balance of payment.
Answer:
Meaning of balance of payment:
The balance of payment of a nation consists of the payments made, within a particular period of time between the residents of the country and the residents of foreign countries.

Following are the causes of adverse balance of payment in India:
1. Increase in imports of petroleum products:
Oil producing countries are increasing the price of petroleum products every year. Along with it the consumption of petroleum products is also increasing day by day. Due to this import is done on lkrge scale.

2. Increase in import of machines:
Due to economic planning there is rapid growth in industrialization and progress in agricultural development. For this the need of machines was felt. Due to this reason more import has to be done.

3. Less increase in export:
The export did not increase according to expectations which is one of the causes of unfavourable balance of payment.

4. International loans and investment:
India has taken loan for developmental purpose. To repay the principal amount and interest, foreign exchange has to be paid. It gave rise to the situation of adverse balance of payment.

Question 4.
Suggest measures to improve the condition of adverse balance of payment
Answer:
Measures or method to correct adverse balance of payment : Following steps should be taken to improve adverse balance of payment in India :

1. Encouragement to export:
The government should encourage the export.

• The trade policy should be export oriented
• For this export tax should be reduced or some concession should be given for export of some goods
• Economic assistance should be provided to the industries of the country
• Advertisement should be done in foreign countries for the products.

2. Reduction in import:
India should reduce imports. For this import duty should be raised so, that imported goods will become expensive and people will be discouraged to purchase them. Domestic products should be discouraged reduce the imports. It will give rise to favourable balance of payment.

3. Foreign debt:
To remove adverse balance payment government can take foreign loan. But taking loan is a temporary solution of it.

4. Exchange control:
For keeping the balance payment exchange control is one method. By controlling exchange we can reduce import and increase export.

Question 5.
Give arguments in favour and against fixed exchange rate.
Or
Give arguments in favour of fixed exchange rate.
Answer:
Follo’wing are the points which can be studied in favour of fixed exchange rate :

1. Encouragement to international trade:
Under fixed exchange rate both importer and exporter know about the amount he has to pay and how much he will be getting. Thus in fixed exchange rate international trade develops in a balance way. Here there is less risk.

2. Encouragement to foreign capital:
If the exchange rate is stable foreign exchange can easily flow into the country because investor is not scared of getting less amount than what is fixed. There is no fear of bearing of loss if the rate of exchange is reduced.

3. Capital formation:
If the foreign exchange rate is fixed there is a favourable effect on internal condition of the country. There is no fear of inflation. In industry demand of capital is increased, savings is also increased. Thus rate of capital formation increases. It gives rise to the development of the country.

4. Exchange system:
If the exchange rate is fixed it does not give encouragement to the tendency of gambling. Thus government can control the exchange system in proper way.

5. Essential for export countries:
Some of the country depend on the income coming from export. Half the national income of such countries comes from exports. For countries like England, Denmark, Japan etc. fixed rate of exchange is very essential otherwise there will be adverse effect on its development.

Following points are there against the fixed rate of exchange :

1. Controlled economic system:
For fixed rate of exchange it is compulsory to have strict controlled over economic system. If it is not possible then we will have to make changes in exchange rate.

2. Unfavourable effect on economic progress:
The main aim of fixed rate of exchange is to maintain stability in exchange rate. In this situation sometimes national income, employment policy, price level etc. are considered as secondary.

3. Corruption:
To maintain fixed exchange rate many restriction are imposed in the country. Due to strict restriction there is always possibility of corruption in the society.

Question 6.
Differentiate between Balance of Trade and Balance of Payment.
Answer:
Differences between Balance of Trade and Balance of Payment:

Balance of Trade:

• The difference between exports and imports is called balance of trade.
• It refers to detailed description of imports and exports only.
• It includes visible items only.
• It may be favourable and unfavourable.
• If balance of trade is not favourable it is not a cause of great concern.
• Balance of trade is a part of balance payment.

Balance of Payment:

• The difference between the total receipts of foreign exchange and total payment of foreign exchange is called balance of payment.
• It comprises not only exports and imports but also services, capital, gold etc.
• It includes visible as well as invisible items both.
• It is always balanced.
• If the balance of payment is not favourable it is a cause of great concern for the nation.
• The concept of balance of payment is broader.

Question 7.
Differentiate between devaluation and depreciation.
Answer:
Differences between devaluation and depreciation:
Devaluation means lowering the value of one’s currency in terms of foreign currency. In this case, the domestic value of currency remains constant but its value in terms of foreign currencies fall. On the other hand, the fall in the price of foreign exchange under flexible exchange rate is known . as depreciation. For instance, if the equilibrium rupee – dollar exchange rate was Rs. 45 and now it has become Rs.50 due to rise in demand for dollars, then the rupee has depreciated against dollar.

Question 8.
What is the marginal propensity to import when M = 60 + 0.06Y? What is the relationship between the marginal propensity to import and the aggregate demand function?
Answer:
M = 60 + 0.6Y (Given)
M = \(\overline { m } \) + mY
Hence, m = 0.6
Where, m = Marginal propensity to import

Relationship:
There is positive relationship between marginal propensity to import and aggregate demand function. Marginal propensity of income spent. Thus,
m = \(\frac {∆m}{∆n}\)

Question 9.
Explain, why:
G -T = (S^g -1) – (X – M)?
Answer:
G -T = (Sf -1) – (X – M)
Here, G = Government expenditure
T = Taxes
S^g = Saving of government
I – Investment
S^g-I = Net Saving
X = Exporters
M = Importers
X – M = Balance of trade.
The given equation states that net government expenditure equals net government savings and balance of trade. It implies that net government expenditure is financed by government savings and trade deficit. Hence, the given equation is correct.

Question 10.
Should a current account deficit be a cause for alarm? Explain.
Answer:
When a country runs a current account deficit, then he must see whether there has been a decrease in saving, increase in investment or an increase in the budget deficit. There is reason to worry about a country’s long prospects of the trade deficit reflects smaller savings or a larger budget deficit. The deficit could reflect higher private or government consumption. In such cases, the country’s capital stock will not rise rapidly enough to yield enough growth it needs to repay its debt. There is less cause to worry, if the trade deficit reflects a rise in investment, which would build the capital stock more quickly and increase future output.

Question 11.
Distinguish between Balance of Trade and Balance on Current Account.
Answer:
Differences between Balance of Trade and Balance on Current Account:

Balance of Trade Account:

• Balance of trade account records the difference between value of imports and exports of material goods (visible items). lateral transfer (visible and invisible)
• Balance of trade is a part of balance on current account. So, it is a narrow concept.

Balance on Current Account:

• Balance on current account records the difference between receipts and payments of foreign exchange on account of goods, services and uni – items).
• Balance on current account is a wide concept.

Question 12.
If inflation is higher in country A than in country B and the exchange rate between the two countries is fixed, what is likely to happen to the trade balance between two countries ?
Answer:
Effect of inflation on the trade balance:
As the inflation is higher in country A than country B, so the prices of country A will be higher as compared to those of country B. In this case exports of A country will fail. The aggregate demand will fall and output and income will fall. Comparatively less price in country B will make its products less expensive and hence again increases w.e.f. net export and domestic output and income. The trade balance of country A will become deficit.

Balance of Payments Long Answer Type Questions

Question 1.
Write the components of Balance of payment.
Answer:
The Balance of payment of a nation consist of the payments made, within a particular period of time between the residents of that country and the residents of foreign countries. (MPBoardSolutions.com) In other words, it is an account of transactions involving receipts from foreigners on one side and payments to foreigners on the other side. The farmer relates to the international income of a country, they are called “credits” and since the later relates to the international out go, they are call “debits”.

Balance of payment includes all other payments apart from export and import. For example fee of banks, interest, profit, transfer of capital etc. are also included in balance of payment.

Question 2.
Write the main components of capital accounts.
Answer:
The main components of capital accounts are :

1. Borrowings and lending to and from abroad: It includes :
All transactions relating to borrowings from abroad by private sectors, government, etc.
All transactions of lending to abroad by private sectors and government.

2. Investment to and from abroad:
Investments by rest of the world in shares of
Indian companies, real estate in India etc.
Investments by Indian residents in shares of foreign companies, real estate abroad, etc.

3. Change in foreign exchange reserves:
The foreign exchange reserves are the financial assets of the government held in the central bank.

Question 3.
Explain the factors affecting fluctuations in foreign exchange.
Answer:
The factors affecting fluctuations in foreign exchange :

1. Banking related effects:
Banks through their functions affect the exchange rate. If the commercial bank float bank draft and other credit letters in large quantity then the demand for foreign exchange increases and the exchange rate of the country currency decreases. On the other hand, when foreign exchange bank floats credit letters against the country then the demand for home currency increases and the exchange rate becomes favourable for the country.

2. Change in prices:
In comparative view the change in prices results in the change of exchange rate of the country.

3. Impact of imports and exports:
Changes in the import and export quantity of country has a direct impact on the countries exchange rate if export increases in comparison to import the demand for foreign exchange. (MPBoardSolutions.com) If exports increase in comparison to imports the demand for foreign exchange increases and the countries exchange rate becomes favourable. But on the other hand if imports increase then the demand for country currency increases in the foreign country and this becomes unfavourable for the country.

4. Impact of speculation:
The changing trend in speculation trends also have an impact on exchange rate. In short period the.high rate of exchange leads to speculation tendencies. The uncertainty of exchange rate in international money market also encourages speculative motive.

5. Flow of capital:
The flow of capital from a country also affects the exchange rate. Flow of capital from one country to another to earn high profits is possible in short period or flow of capital to foreign countries for investment in the long period in the foreign country is also possible.

Question 4.
Explain visible and invisible export and import.
Answer:
Visible Import and Exports:
Such goods are included in visible imports and exports whose account is maintained in the register of ports. By seeing them we can find out the values of import and export done throughout the year. (MPBoardSolutions.com) In it only the export and imports of goods are kept.

Invisible Import and Exports:
In invisible export and import we include services which exchange are included. They are banking services, insurance, shipping services, education in foreign, medical facilities, tourism, interest, profit, military assistance, foreign donation, penalty etc. whose account is not maintained on ports are included in it.

Question 5.
Suppose C =100 + 0.75Y, 0T = 500, G = 750, taxes are 20% of income. X = 150, M = 100 + 0.2Y. Calculate equilibrium income, the budget deficit or surplus and the trade deficit or surplus.
Answer:
C = 100 + 0.75 YD
Here, C = 100, C = 0.75, I = 500, G = 750, X = 150, M = 100 + 0.2Y
Tax income (r) = 20%
Income (Y) = C + C (1 – t) Y +1 + G + (X – M)
or Y = 100 + 0.75 (1 – 0.2)Y + 500 + 750 + (150 – 100 – 0.2Y)
or Y = 100 + 0.75(0.8) Y + 500 + 750 + 150 – 100 – 0.2Y
or Y= 100 + 0.6Y+ 1300 – 0.2Y
or = 1400 + 0.4Y
or Y – 0.4 Y = 1400
or 0.6Y = 1400
or Y = \(\frac {1400}{0.6}\) = 2333
Deficit budget = Govt. expenditure Tax – (G) – Tax
= 750 – 2333 of 20 %
= 750 – 467 = 283
M = 100 + 0.2Y
= 100 + 0.2 (2333)
= 100 + 467 = 567
So, Trade deficit = M – X = 567 – 150 = 417.

MP Board Class 12th Economics Important Questions

MP Board Class 12th Economics Important Questions Unit 9 Government Budget and Economy

Government Budget and Economy Important Questions

Government Budget and Economy Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
The duration of Government budget is :
(a) 5 years
(b) 2 years
(c) 1 year
(d) 10 years.
Answer:
(c) 1 year

Question 2.
Budget is presented in the Parliament by :
(a) Prime Minister
(b) Home Minister
(c) Finance Minister
(d) Defence Minister.
Answer:
(c) Finance Minister

Question 3.
Budget speech in Lok Sabha is given by :
(a) President
(b) Prime Minister
(c) Finance Minister
(d) Home Minister.
Answer:
(c) Finance Minister

Question 4.
Professional tax is imposed by :
(a) Central Government
(b) State Government
(c) Municipal Corporation
(d) Gram Panchayat.
Answers:
(b) State Government

Question 5.
From the following which is included in the direct tax :
(a) Income Tax
(b) Gift Tax
(c) Both (a) and (b)
(d) Excise Tax.
Answer:
(c) Both (a) and (b)

Question 6.
Who issues 1 rupee note in India :
(a) Reserve Bank of India
(b) Finace Ministry of India
(c) State Bank of India
(d) None of these.
Answer:
(b) Finace Ministry of India

Question 2.
Fill in the blanks:

1. …………………… is a document containing income and expenditure of the government.
2. Income tax is …………………… tax.
3. …………………… tax is levied on the value of the goods.
4. Service tax is levied by the ……………………
5. budget is considered good for the country.
6. Finance bill contains …………………… proposals.
7. Government budget is presented on the last day of ……………………

Answer:

1. Budget
2. Direct
3. Advalorem
4. Central
5. Deficit
6. Tax
7. February.

Question 3.
State true or false :

1. Deficit budget is not considered as a good budget.
2. Electricity tax is levied by the State Government.
3. Budget speech is given by the Finance Minister.
4. Central excise duty is direct tax.
5. Interest payment is a planned item.
6. During deflation surplus budget is made.
7. Rail budget is generally not included in the annual budget.

Answer:

1. False
2. True
3. True
4. False
5. False
6. True
7. True.

Question 4.
Match the following

Answer:

1. (b)
2. (d)
3. (a)
4. (e)
5. (c)

Question 5.
Answer the following in one word/sentence :

1. Write meaning of surplus budget.
2. Expenditure on education is considered as?
3. Who passes the budget presented by the Finance Minister every year?
4. Which tax was levied by the government on July 2017?
5. For how many years government makes budget?
6. What is the full form of G.S.T.?
7. Land Revenue is levied by whom?
8. What is the name gives to budget?

Answer:

1. More income and less expenditure
2. Developmental
3. Parliament
4. G. S. T
5. 1 year
6. Goods and Service Tax
7. By State Government
8. Master Finacial Scheme of Government.

Government Budget and Economy Very Short Answer Type Questions

Question 1.
What do you mean by government budget? How many types are there?
Answer:
A budget is the statement of financial plan of the government for a financial year (1st April to 31st March). It indicates the revenue expenditure estimates for the next financial year of the government.

Budget is of two types:

1. Capital budget
2. Revenue budget.

Question 2.
What do you mean by primary deficit?
Answer:
Primary deficit is the difference between fiscal deficit and interest payments. It indicates how much government borrowing is going to meet expenses other than interest payments. It is often used as the basic measure of fiscal responsibility.
Primary Deficit = Fiscal Deficit – Interest payments

Question 3.
What is tax?
Answer:
A tax is a compulsory contribution which is given by the people to the government in order to meet the expenditure on the welfare of the citizens.

Question 4.
What is deficit budget?
Answer:
When the expenditure of the government is more than the income of the government, it is called deficit budget.

Question 5.
What do you mean by supplementary budget?
Answer:
Supplementary budget is prepared for the temporary period. It is prepared during the period of emergency like flood, war, earthquake etc.

Question 6.
What do you mean by zero primary deficit?
Answer:
When government has to take loan only to fulfill the liability of interest it is called zero primary deficit.

Question 7.
What do you mean by vote on account?
Answer:
Special arrangement is made under which special power is vested with lok sabha to sanction some amount as advance till the financial budget is passed for the next year.

Question 8.
What is tax evasion?
Answer:
When people do not pay tax by hiding income it is called tax evasion.

Question 9.
What do you mean by surplus budget?
Answer:
When the income of the government is more than expenditure of the government in budget, it is called surplus budget.

Question 10.
What is a balanced budget?
Answer:
Budget in which income and expenditure of the government is equal is called balanced budget.

Question 11.
Write the tax multiplier.
Answer:
Tax multiplier = \(\frac {-c}{1 – c}\)

Question 12.
What do you mean by debt trap?
Answer:
Generally developing countries take loans from foreign countries to fulfill their projects and plans. Developing countries have to pay debt along with the interest on it. To pay this amount again government has to take loan. Thus, principal amount goes on increasing. These countries take loan from one country and pay loan of other country. Thus these countries go in the clutches of debt. This is called debt trap.

Question 13.
Write the main revenue sources.
Answer:
Public revenue:
By public revenue we mean all those income of the government which are essential for government expenditure. Public revenue can be divided into two parts :

1. Revenue receipts
2. Capital receipts.

1. Revenue receipts (Items of income) are of two types :

(A) Tax revenue : It includes all direct and indirect taxes which are imposed by the central government. For example, Income Tax, Corporation Tax, Production tax.

(B) Non – tax revenue :

• Interest receipts
• Dividends and Profits
• Foreign grants
• Fiscal services, Economic services, Subsidiary assistance.

Question 14.
Give the relationship between the Revenue deficit and the Fiscal deficit.
Answer:
Revenue deficit refers to the excess of Government’s revenue expenditure over revenue receipts whereas fiscal deficit is the difference between the government’s total expenditure and its total receipts excluding borrowings.

Question 15.
Explain why public goods must be provided by the government.
Answer:
Public goods must be provided by the government as they cannot be provided through market mechanism i.e., by transactions between individual consumer and producers.

Question 16.
Explain the relation between government deficit and government debt.
Answer:
Relation between government deficit and government debt: The government deficit and government debt are closely related. The government deficit in a flow concept, but it adds to the stocked debt. If the government continues to borrow year after year there is an accumulation of debt. It implies that government has to pay more and more by way of interest. These interest payment contribute to the debt. Thus, deficit is the cause and effect of debt.

Question 17.
Explain the concept of Deficit budget.
Answer:
Deficit budget: It is the budget in which government receipts are more than government expenditure.
Formula = Expected public income < Expected public expenditure.

Government Budget and Economy Short Answer Type Questions

Question 1.
What is a government budget? Write its objectives. (Delhi, Foreign 2013)
Answer:
“A budget is the statement of the financial plan of the government for a financial year” (1st April to 31st March). It indicates the revenue expenditure estimates for the next financial year of the government. The main objectives of budget are as follows :

1. Reallocation of financial resources.
2. Removal of inequality of income and wealth.
3. Stabilization of price level.
4. Management of public enterprises.
5. Expansion of employment opportunities.

Question 2.
How inequalities in income can be removed through budget?
Or
What is the role of budget in removing income inequalities? (Delhi, All India 2011, Foreign 2012)
Answer:
Fiscal policy implies the income and expenditure policy or the budgetary policy of the government. It is a branch of public finance which deals with the types of financial statements made by any government about its probable revenue and expenditure during a given year.

Through their fiscal policies government can play a significant role in reducing inequality of income and wealth as well as inequality of opportunity. Both tax and spending policies can alter the distribution of income over both short term and medium term. Government need to reform the policies by imposing more taxes oh riches sections and to reduce the burden of tax on poor with the motive of economic welfare of the poor people.

Question 3.
Explain in brief how economic stability can be obtained by government budget? (All India 2011)
Answer:
Government budget is used to prevent business fluctuations of inflation or deflation to achieve the objective of economic stability. The government aims to control the different phases of business fluctuations through the budgetary policy. Policies of surplus budget during inflation and deficit budget during deflation helps to maintain stability of prices in the economy.

Question 4.
What is the role of government in Reallocation of Resources? Explain. (Delhi 2012)
Answer:
Through the budgetary policy, Government aims to reallocate resources in’ accordance with the economic and social priorities of the government. Government can influence allocations of resources through:

1. Tax concessions or subsidies:
To encourage investment, government can give tax concessions subsidies etc. to the producers, example Government discourages the production of harmful consumption goods through heavy taxes and encourages the use of khadi products ‘by providing subsidies.

There is disequilibrium in the balance of payments when imports are more and exports are less. With demonitization of Indian rupee imports have become costlier, efforts can be made to make balance of payments favourable. But this cannot be done again and again because by this demand of our currency will decrease.

Question 5.
Explain four types of public expenditure.
Answer:
Following are the types of public expenditure :

1. Developmental expenditure:
Under it we include those expenditure which are done for the economic development and social welfare of people. It includes education, medicine, industry agriculture, transportation roads, canals, water welfare, electricity etc.

2. Non – development expenditure:
This expenditure includes that expenditure which is done on administration, on security and legal procedure of the government. It includes salaries of police department, military department, interest on loans, pension etc.

3. Plan expenditure:
It includes expenditure to be incurred during the year on programmes under the five year plan by planning commission. In this expenditure investors and consumers both are included. For example, economic activities like agriculture, industry transportation, communication etc. It also includes social welfare activities like education, family welfare, information and communication, drinking water, cleanliness, health etc.

4. Non – plan expenditure:
It includes all those expenditure other than plan expenditure. It includes debt given to State Government and others, expenditure on maintenance of property, expenditure on purchase of shares.

Question 6.
Differentiate between Direct Tax and Indirect Tax
Answer:

Question 7.
Differentiate between Revenue Expenditure and Capital Expenditure.
Answer:
Differences between Revenue Expenditure and Capital Expenditure :

Revenue Expenditure:

• Revenue expenditure is a current expenditure incured on civil administrations, defence forces, public health and education.
• It is of recurring type of expenditure. It is incurred regularly.
• It is called non – developmental expenditure.

Capital Expenditure:

• It refers to expenditure which leads to creation of assets or reduces liabilities.
• It is a non – recurring type of expenditure.
• It is called developmental expenditure.

Question 8.
Differentiate between Developmental and Non – Developmental Expenditure.
Answer:
Differences between Developmental and Non – Developmental Expenditure:

Developmental Expenditure:

• It is incurred on economic and social development of the country.
• Expenditure on agriculture, industries, transport, etc. are included in it.

Non – Developmental Expenditure:

• Its nature is non – developmental type.
• Expenditure on administrative services like police defence, grants to government, etc. are included in it.

Question 9.
What do you mean by budget? Write its characteristics.
Answer:
Origin of the word in India:
The word ‘budget’ has been derived from the French word ‘Bougette’, which means small bag. It symbolizes a bag containing the financial proposals. In England, the chanceller used to bring economic proposals and statements in a bag; In 1773, finance minister of Britain, Robert Walpole opened his leather bag for the budget proposal to take place in Parliament. From that it becomes popular in India.

Characteristics of budget : Following are the characteristics of budget:

1. Annual plan of income and expenditure : It is a description of annual income and expenditure of the government for the next financial year. It is a detailed description.
2. Fixed period : Budget is prepared before a fixed period. It is presented before the Parliament by finance minister on the last day of the month of February. It is related to the definite fixed period.
3. Financial discussion: In budget only financial discussion takes place.Other matters are not discussed here.
4. In advance : Budget is prepared in advance for the period during which it is to operate. It is an annual financial action plan for the next financial year.
5. Balance budget : Balanced budget is the symbol of economic stability of the country.

Question 10.
Write the objectives of budget.
Answer:
The objectives of budget are as follows :
1. Reallocation of financial resources:
The government reallocates the financial resources to achieve the desired goals. It is the primary responsibility of the government to build a sound socio – economic infrastructure regarding health housing, education and raising the standard of living of people. Government imposed more taxes on those items which are harmful for people on the other hand it may reduce the taxes which are useful from social point of view.

2. Removal of inequality of income and wealth:
Every nation tries to bring equality between the various sections of the people and to bridge the gap between poor and rich. Through subsidies, taxes government can remove their inequalities. The main objective of Budget is to fill the gap of rich and poor.

3. Stabilisation of price level:
It is the responsibility of the government to stabilise the price level in the country. Unnecessary fluctuation in the prices of goods and services adversely affect the economy. Through the budget the government can effectively control the price level and bring about stability in it.

4. Management of public enterprises:
The government looks after certain departments such as railways, post and telegraph, electricity, defence etc. The budget of the government makes special provisions for such public enterprises in order to safeguard the interest of public.

5. Expansion of employment opportunities:
Government throughout budget create the employment opportunities to people. Various employments oriented and productive programs can be implemented for this purpose.

Question 11.
Differentiate between Progressive Tax and Regressive Tax.
Answer:
Differences between Progressive Tax and Regressive Tax :

Progressive Tax:

• In progressive tax the rate of the tax increses as the taxable income increases.
• The burden of it is more on rich people.
• They are justified because they reduce inequalities of income.

Regressive Tax:

• In regressive tax the rate of the tax decreases as the taxable incomes increases.
• The burden of it is on poor people.
• These are not justified because they increase inequalities.

Question 12.
Write difference betw een Revenue Receipts and Capital Receipts. (Foreign 2013)
Answer:
Differences between Revenue Receipts and Capital Receipts :

Question 13.
Write a note on Surplus budget, Balance budget and Deficit budget.
Answer:
A budget is the statement of the financial plan of the government for a financial year. It indicates the revenue expenditure estimates for the next financial year. The different types of budget are :

1. Surplus Budget – When in budget the income of the government is more than expenditure of the government, it is called Surplus Budget.
2. Balance Budget – Balance budget is said to be balance when government revenue and expenditure are balanced.
3. Deficit Budget – If the expenditure of the government is more than the income of the government, it is called the Deficit Budget.

Question 14.
Does public debt impose a burden? Explain.
Answer:
Public debt does not impose a burden all the times. Only in the following situation, it imposes a burden. When government sectors to public debt, the government transfers the burden to reduce consumption on future generation, because the government may decide to pay off deut in future by raising taxes. Taxes reduce the savings and capital formation and growth. Thus, the debt acts as a burden on future generation.

Question 15.
(a) The fiscal deficit given the borrowing requirement of the government. Explain.
Answer:
Fiscal deficit gives the borrowing requirement of the government’s total expenditure and its total receipts excluding borrowing. The fiscal deficit has to be financed through borrowing. Thus, it indicates the total borrowing requirements of the government from all sources.

(b) Are fiscal deficits inflationary? (NCERT)
Answer:
It is not correct to that all deficits are necessarily inflationary. If the fiscal deficit results in higher demand and greater output, the fiscal deficit will not be inflationary. However, if the firms are unable to produce the higher quantities that are being demanded to due fiscal deficits, prices will rise resulting the inflationary.

Question 16.
We suppose that: C= 70 + 0.70YD, I = 90, G = 100, T = 0.10 Y
(a) Find the equilibrium income, (b) What are tax revenues at equilibrium income? Does the government have a balanced budget ?
Solution:
(a) Y = \(\frac {1}{1 – 0.70}\)(70 + 90 + 100)
Y = \(\frac {1}{0.30}\)(260)
Y = \(\frac {260}{0.30}\) = 866.66

(b) Tax revenue on balance budget (T) = 0.10 Y T = 0.10 (866.66) T = 86.66.

Question 17.
Suppose that for a particular economy investment is equal to 200, government purchases are 150, net taxes i.e., lump sum taxes minus transfer in 100 and consumption is given by C = 100 + 0.75. (a) What is the level of equilibrium multiplier? (b) Calculate the value of government expenditure multiplier and the tax multiplier, (c) If government expenditure increases by 200, And the change in equilibrium income.
Answer:
(a) The government directly affects the level of equilibrium income in two specific ways : 1. Purchase of goods and services and 2. Taxes and transfers. Taxes lower the consumption expenditure and disposable income. Hence, we use the following formula for calculating the level of equilibrium income:
Formula: Y = \(\frac {1}{1-c}\)(C – CT + CTR+ 1 + G)

(b) Govt expenditure multiplier:
\(\frac { ∆Y}{∆G}\) = \(\frac {1}{1-c}\)
\(\frac { ∆Y}{∆G}\) = \(\frac {1}{ 1-0.75}\) \(\frac {1}{0.25}\)
Tax multiplier \(\frac { ∆Y}{∆G}\) = \(\frac {-C}{1-c}\)
\(\frac { ∆Y}{∆G}\) = \(\frac {-0.75}{ 1-0.75}\) = \(\frac {-0.75}{ 0.25}\) = – 3

(c) If income of Govt, increases by 200 :

Question 18.
In the equation given in question 9, calculate the effect on output of a 10 increase in transfers and 10 increase in lumpsum taxes. Compare the effects of two.
Solution:
Transfer multiplier, = \(\frac {C}{1-C}\)
= \(\frac {0.80}{1-0.80}\)
= \(\frac {0.80}{0.20}\)
= 4
Increase in transfer = 10%
Hence, increase in output = 10%
Tax multiplier = 4
Decrease in output = 10 x 4 = 40%
or
Y = \(\frac {1}{0.20}\)(20 – 8 + 88 + 30 + 50)
Y = 5 x 188 = 940
Increase lump sum, its effect,
or Y = \(\frac {1}{1-0.80}\)(20 – 8 + 80 + 30 + 50)
Y = 5 x 172 = 860.
Hence, we find that effected change in transfer and change in taxes are equal. It is due to fact that their size of changes as well as multiplier are equal.

Question 19.
What do you understand by Goods and Service Tax (G.S.T.)? How is G.S.T. better than old system of taxation? Explain its types.
Answer:
(a) The Goods and Services Tax (G.S.T.) is a value Added Tax (VAT) levied on most goods and services sold for domestic consumption. The G.S.T. is paid by consumers, but it is remitted to the government by the businesses selling the goods and services:

G.S.T. in comparison with old taxation system :

1. In place of old taxation system, G.S.T. will become one tax economy.
2. The tax structure will be simplified with G.S.T.
3. G.S.T. will save both time and money.
4. The growth rate of economy will show a rapid increase with G.S.T.
5. But for the time being, the G.S.T. would be expected to increase the inflation rate in comparison to the old tax system.

For Goods and Services Tax, G.S.T., U.T.G.S.T. Act and S.G.S.T. tax are passed.

Government Budget and Economy Long Answer Type Questions

Question 1.
Explain the types of budget.
Answer:
The types of budget are as follows :
1. Central budget:
Central budget is prepared by Central Government. It is the numerical statement of income and expenditure done by central government. In India Central budget is presented in two parts:

• General budget
• Railway budget.

2. State budget:
State budget is prepared by State Government. State Government takes the help from Central Government.

3. Revenue budget and Capital budget:
In revenue budget we include the expenditure and income related to revenue of the government. On the other hand in capital budget the capital expenditure and capital income is included.

4. Supplementary budget:
Supplementary budget is prepared for the temporary period. It is prepared during the period of emergency like flood, earthquake and war etc. There is no fixed time for it.

5. Balanced budget and Imbalanced budget:
Balance budget is that budget where income and expenditure of the government is equal. Imbalanced budget is that budget where expenditure is more or less than income of the government. If the expenditure is more than income it is called deficit budget and if the income is more than the expenditure it is called surplus budget.

Question 2.
Explain the procedure of the budget.
Answer:
Under the budgetary procedure in India we can study the following heads:

1. Preparation of budget : The preparation of budget involves the following steps :

• Sending estimate forms by finance minister to all ministers and their department’s heads to get the estimates of revenue and expenditure required for the next financial year.
• Preparation of estimates by departmental heads : It includes revenue and expenditure of previous year budgetary estimate for next coming year.
• Preparation of consolidated estimate by the various ministers and sending them to finance minister.
  Scruting report estimates by A.G. of India and sending the same to finance ministry.

2. Presentation of the budget : In India the budget is presented in two parts :

• General budget and
• Rail budget.

Rail budget is always present before the general budget. General budget presented on the last day of the month of February at 5 p.m. generally 28th in February.

3. Discussion on the budget:
Budget is put before the Parliament for discussion. In the processes of passing the budget, the discussions on various items continues for 3 – 4 days. Presently different committees are formed. For the discussion and finance minister gives his final reply on the budget.

4. Voting on budget:
After the general discussion the budget is put for voting. The members of parliament give their speeches for and against the budget before voting. There after voting is held for passing the budget.

5. Appropriation bill:
The finance minister presents appropriation bill. According to the constitution no amount from the Reserve fund of India can be withdrawn without passing the appropriation bill in the Parliament.

6. Financial bill:
All the financial proposals for the coming year are included in a bill which is known as financial bill. This bill is generally presented immediately after the presentation of budget in the Lok Sabha. If this bill is not passed by the Parliament f ur government L not supposed to spend any amount.

7. Vote on account:
Special arrangement is made under which special power is vested with Lok shabha to snetion some amount as advance till the final budget is passed for the next year.

8. Implementation of budget:
After the budget is passed, it is implemented by the government for which the following steps are taken :

• Collection of revenue
• Preparation of accounts in
• Audit by A.G. (Auditor General).

Audit by comptroller and Auditor General of India presents their report before the Parliament which comprise the receipt of revenue, expenditure, loans taken.

Question 3.
Write the tax revenue sources of Public Revenue:
Answer:
Following are the sources of Public Revenue :
Tax:
Taxes are neither a fees nor a penalty because it is neither taken by the government to give any additional benefits nor taken as a fine. Taxes are compulsory contribution which are given by the people to the government in order to meet the expenditure on the Welfare of the citizens.

Types of taxes : Taxes are of following types :

• Progressive tax – In progressive tax the rate of my increases as the income increases
• Proportional tax – Proportional taxes are those taxes whose impact and incidence falls equally on both the sections of the society.
• Regressive tax – The rate of taxation decreases with the increase in income. The burden of text falls more heavily on poor than on rich.
• Direct taxes – These are those taxes in which the impact of the tax and incidence of tax is on the same person.

Question 4.
What do you understand by Non – tax sources of public revenue?
Answer:
Following are the non – tax sources of public revenue:

1. Fees, licence and permit:
Government gets non – tax revenue from fees licence fee and payment made for permits.

Fees – Registration fee for land, death and birth registration fees, passport fees are included in it.

Licence and permit – Fee is that fee which is paid by people to government after giving permission by the government to the people to do something. For example: Driving licence, import licence etc.

2. Fines:
Fines are collected by the govt, for breaking rules of the country. The main aim of this is not to collect money but to teach people lesson about it.

3. Income from public enterprise: Government may raise funds from many sources like Railways, Postal department, Steel Plants fertilizer Corporations, Indian Oil department etc. Government sells products of it and gets profit from it.

4. Gifts and grants: The government may raise the funds from others. During calamities like flood, earthquake etc. citizens and some NGO’s give help to the government . For example : W.H.O., UNESCO etc. they give assistant also during this period.

5. Notes issues:
Sometimes government prints extra notes and increase the treasury. Reserve Bank of India has got the right of printing notes and minting coins.

6. Stamp, registration and land revenue: The receipts of stamps, registration and land revenue is the another source of non – tax revenue. The stamp receipts of Supreme court is also the income of the central government.

7. Interest, receipts : Interest earned by  the government from the loans given to States, Union territories. Railways, Post and Telegraph are included in it.

8. Dividends: This includes the share from profits of various undertakings in which the central government has done investments example SAIL, ONGC etc.

9. Administrative receipts:
The central government provides a number of services to people like health, medical, education etc. The government earns certain income from these services. For example; court fees, registration fees.

Question 5.
Consider an economy described by the following functions. C = 20 + 0.80 Y, I = 30, G = 50, TR = 100.
(a) Find the equilibrium level of income and the autonomous expenditure multiplier in the model,
(b) If the government expenditure increases by 30, what is the impact on equilibrium income?
(c) If a lump sum tax of 30 added to pay for increase in government purchases, how will equilibrium income change?
Answer:
C = 20 + 0.80y
I = 30
G = 50
TR = 100
(a)
Y = \(\overline { C } \) + CY – (T – TR)
Y = 20 + 0.80 (Y + TR) + I + G
Y = 20 + 0.80 (Y + 100) + 30 + 50
Y = 0.8Y + 180
Y = \(\frac {180×100}{200}\)
= 900
The equilibrium level of income is 900. Autonomous expenditure multiplier.
= \(\frac {1}{1 – C}\)
= \(\frac {1}{1-0.08}\)
= \(\frac {1}{0.20}\)
= 5
Increase in equilibrium income = AG x Expenditure multiplier = 30 x 5 = 150
Tax multiplier = \(\frac {-C}{1 – C}\) = \(\frac {-0.08}{1-0.08}\) = \(\frac {-80}{0-20}\) = -4
Decrease in equilibrium income = ∆T x Tax Multiplier
= 30 x 4 = 120.
or
Y = \(\frac {1}{0.20}\)(180)
Y = 5 x 180 = 900
autonomus multiplier \(\frac { ∆Y}{∆G}\)= \(\frac {1}{1 – C}\)
or
\(\frac { ∆Y}{∆G}\) = \(\frac {1}{1-0.80}\) = \(\frac {1}{0.20}\) = 5

(b) Expenditure of govt, increase by 30 :
(∆Y) = \(\frac {1}{1 – C}\) ∆G
or
∆Y = \(\frac {1}{1-0.80}\) x 30
= \(\frac {1}{0.20}\) x 30 = 5 x30 = 150
New income = 900 + 150 = 1,050
So, it is clear that by 30 it become 150 to 1,050.

(c) Lump sum 30 is added then :
Change in balance income (∆Y) = \(\frac {-C}{1 – C}\) ∆T
or
∆Y = \(\frac {-0.08}{1-0.08}\) x 30
= \(\frac {-0.08}{0.20}\) x 30 = -4 x 30
= 1 – 120
= 900 – 120 = 780

MP Board Class 12th Economics Important Questions

MP Board Class 12th Economics Important Questions Unit 8 Money and Banking

Micro Economics Money and Banking Important Questions

Micro Economics Money and Banking Objective Type Questions

Question 1.
Choose the correct answers:

Question 1.
“Money is what money does”. Who said this:
(a) Hartley Withers
(b) Harte
(c) Prof. Thomas
(d) Keynes.
Answer:
(a) Hartley Withers

Question 2.
Function of money is:
(a) Medium of exchange
(b) Measure of value
(c) Store of value
(d) All of the above.
Answer:
(a) Medium of exchange

Question 3.
Meaning of money supply is:
(a) Money deposits in the bank
(b) Cash available with public
(c) Savings in the post office
(d) All of the above.
Answer:
(d) All of the above.

Question 4.
What is the Central Bank of India:
(a) Commercial Banks
(b) Central Bank
(c) Private Bank
(d) None of these.
Answer:
(a) Commercial Banks

Question 5.
Through which method we can withdraw money from the bank:
(a) Drawing letter
(b) Cheque
(c) A.T.M.
(d) All of the above.
Answer:
(d) All of the above.

Question 6.
Who is the guardian of Indian Banking System:
(a) Reserve Bank of India
(b) State Bank of India
(c) Unit Trust of India
(d) Life Insurance Company of India.
Answer:
(a) Reserve Bank of India

Question 7.
Narasimham Committee is related to what:
(a) Improvement in Taxation
(b) Improvement in Banking
(c) Improvement in Agriculture
(d) Improvement in Infrastructure.
Answer:
(b) Improvement in Banking

Question 2.
Fill in the blanks:

1. Central Bank of India is………………..
2. Bank rate is also known as………………..
3. The bank generates……………….. deposits in credit creation.
4. When CRR decreases, credit creation………………..
5. Measure of deferred payment is ……………….. function of money.
6. Medium of exchange is ……………….. function of money.
7. The static and dynamic function of money is divided by………………..

Answer

1. Reserve Bank of India
2. Redemption
3. Derivative
4. Increases
5. Secondary
6. Primary
7. Paul Einzig.

Question 3.
State true or false:

1. Money is needed for day-to-day transactions.
2. The precautionary demand for money increases with the proportionate increase in income.
3. Reserve Bank of India provides loan to public.
4. Along with the Reserve Bank of India, Commercial banks are also authorized to issue currency.
5. Reliable money also include cheques.
6. Reserve Bank of India cannot become the owner of any real estate.

Answer:

1. True
2. True
3. False
4. False
5. False
6. True.

Question 4.
Match the following:

Question 5.
Answer the following in one word / sentence:

1. Name the bank that provides long term loans to the farmers.
2. Trade cycle is which evil of money?
3. By increasing liquid fund ratio, which will be the effect on money supply?
4. “The Banks are not only generators of money but are also creators of money”.
5. Who has the right to issues paper money?
6. When was NABARD established?

Answer:

1. Agricultural or Cooperative banks
2. Economic
3. Decreases
4. Sayer’s
5. Central Bank
6. 1982.

Micro Economics Money and Banking Very Short Answer Type Questions

Question 1.
Write two taboo works of Reserve Bank of India.
Answer:
Two taboo works of RBI are:

1. Reserve Bank cannot accept deposits on interest from the public.
2. Reserve Bank cannot provide loans for a fixed term.

Question 2.
What do you mean by overdraft facility?
Answer:
Clients who have current account with the bank are granted” the facility of withdrawing more money than actually lying in their accounts. It is called overdraft. This facility is available to reliable person for a short term.

Question 3.
What is commercial bank?
Answer:
Commercial banks are those banks who are established under the Indian Company Act, and they perform all the functions of banks.

Question 4.
Write the meaning of money.
Answer:
According to Prof. J.M. Keynes, Money is that by the delivery of which debt contracts and price contracts are discharged and in the shape of which a store of general purchasing power is held.

Question 5.
Write any two economic defects of Money.
Answer:
Two economic defects of money are:

1. Money gives birth to trade cycle.
2. Currency is the trust worthy custodian of money.

Question 6.
When was Reserve Bank of India nationalised?
Answer:
Reserve Bank of India was nationalised on 1st January 1949.

Question 7.
Which is the Central Bank of India? When was it established?
Answer:
Central Bank of India is Reserve Bank of India. It was established on 1st April, 1935.

Question 8.
What do you mean by Bank?
Answer:
Nowadays, the word ‘Bank’ is very common and popular so, general public is acquainted with it. Generally, bank means that institution which deals with transactions of money.

According to Prof. Wicksell:
“Bank is the heart and central point of modem currency system”.

Question 9.
Write definitions of money.
Answer:
According to Prof. Hartley Withers, “Money is what money does”. According to Prof. Seligman, “Money is one thing that possesses general acceptability”.

Question 10.
What is the problem of double coincidence of wants in barter exchange?
Answer:
1. Problem of double coincidence:
In barter system, goods are to be exchanged for goods, hence, it is essential that both the parties should need the goods which other has in exchange of their goods, then only the exchange is possible.

2. For example, ‘A’ possesses a chair and ‘B’ possesses a table. Now if ‘A’ wants to exchange his change for a table then he has to search a person, who needs chair in exchange of table. Thus, becomes a complex process for him to find such man.

Question 11.
‘Money is the medium of exchange,’ Explain.
Answer:
Medium of exchange:
This is the most important function of money. It acts as a medium of exchange. All the exchanges of goods and services are taken place in terms of money. (MPBoardSolutions.com) By paying predetermined price, money can be exchanged with the desired goods and services. A money has the general acceptability, therefore, all the exchanges in an economy take place in terms of money. It is because of this reason that money has been defined as generally acceptable purchasing power.

Question 12.
“Measure of value is the main function of money”. Explain.
Answer:
“Measure of value is the main function of money”:
The main function of money is that it measures the value of goods and services. In other words, the prices of all goods and services are expressed in terms of money. In ancient times it was not possible to measure the value of clothes and wheat. With the introduction of money, this difficulty of measurement disappeared and it became very convinient to measure the value of money. Money acts as a unit of account for all goods, wages salaries, interests etc. The national income, capital formation and other are measured in terms of money.

Question 13.
Write the importance of the money as the store of exchange value.
Answer:
Money acts also as a store of value because:

1. Money can be stored very easily. Money is a liquid form of capital. It require less place to store.
2. Money has the merit of general acceptibility.
3. It is convinient to store money.
4. Value of money remains relatively stable. Due to all these reasons money is important.

Question 14.
What is meant by money supply? What are its measures?
Answer:
Money supply refers to the total volume of money held by the public at a particular point of time in an economy.
Measures of money supply are:
M₁ = Currency and coins with public + Demand deposits of Commercial banks + Other Deposites with RBI.
M₂ = M₁ + Savings deposits with post office Saving bank.
M₃ = M₂ + Net time deposits with banks.
M₄ = M₃ + Total deposits with post office saving bank.

Question 15.
Write difference between Scheduled Banks and Non – Scheduled Banks.
Answer:
Differences between Scheduled Banks and Non – Scheduled Banks:

Scheduled Banks:

• Scheduled banks are those banks whose names appear in the second schedule of RBI.
• The paid up share capital together with reserve fund must not be less than Rs. 5 lake.

Non-Scheduled Banks:

• Non – scheduled banks are those banks whose names do not appear in the second schedule of RBI.
• The paid up capital of such banks together with cash reserve is less than Rs. 5 lake.

Question 16.
If in an economy, all the customers of the bank deposit their money in the banks and if all of them withdraw their money from the bank then what will be its effect on the economy?
Answer:
If in any economy, bank customers deposit their money in the banks then there will be shortage of money for production and investment activity. As a result, the process of development will come to a stand still. In the same way, if all the customers withdraw their money from the banks, the banking would collapse and economy will face a problem. If in any bank financial crisis arises then central bank is the only bank to settle this problem and all banking systems will collapse.

Question 17,
Write the meaning of Commercial banks?
Answer:
A commercial bank is a financial institution which accepts deposits from the public and gives loans for purposes of consumptions and investment.

Companies Act, 1949:
A banking company is one which transacts the business of banking which means the accepting for the purpose of lending or investment of deposits of money from the public repayable on demand or otherwise and withdrawal by cheque or otherwise.

Question 18.
Write the types of Commercial bank.
Answer:
There are two types of Commercial banks:

1. Scheduled banks:
Scheduled banks are those banks whose names appear in the second schedule of RBI.

2. Non – scheduled banks:
Non – Scheduled banks are those, banks whose names do not appear in the second schedule of RBI. In other words, those banks which do not fulfill the requisite conditions as explained above are called non-scheduled banks.

Question 19.
What is paper money?
Answer:
Paper money is a country’s official paper currency that is circulated for transaction related purposes of goods and services. The printing of paper money is typically regulated by a country’s Central bank / treasury in order to keep the flow of funds in line with monetary policy.

Paper money is that money which is issued by the order of the government. Paper money is in the form of paper notes or currency notes. In India, the Reserve Bank of India enjoys the sole monopoly of issuing currency notes (Paper money).

Question 20.
What do you mean by money supply?
Answer:
Supply of money is a stock concept. It refers to total stock of money (of all types) held by the people of a country at a point of time.

Question 21.
What do you mean by Fiat money or Legal tender money?
Answer:
Fiat money which serves as money on the basis of fiat (order) of the government It is issued by authority of the government. It includes notes, coins.

Question 22.
What do you mean by C.R.R.?
Answer:
Commercial banks are required under law to keep a certain percentage of their total deposit in the Central bank in the form of cash reserves. This is called Cash Reserve Ratio (C.R.R.).

Question 23.
What do you mean by credit money?
Answer:
It refers to that money of which money value is more than commodity value.

Question 24.
Why is paper money called the Legal tender money?
Answer:
Paper money or Paper notes are called as legal tender money because nobody can refuse its acceptance as medium of exchange. It is legal tender. It means people have to accept it legally for different payments.

Question 25.
What do you mean by high powered money?
Answer:
It consist of currency (Notes and Coins in circulation with public and valt cash of commercial banks) and deposits held by the government of India and commercial banks with R.B.I.

Micro Economics Money and Banking Short Answer Type Questions

Question 1.
“Money is a good servant but a bad master”. Explain.
Answer:
Money is becoming essential part of life, it is controlling our activities in such a way that we are completely under it. It should be means but is has become end of life. Till money acts as servant it is useful for human being but as money goes out of control it becomes harmful for the entire economy. This situation arises when supply of money exceeds its demand. Money becomes master instead of servant. It has become the only means of satisfying our wants. We cannot think of our life without money that is why, it is said that “money is good servant but a bad master.”

Question 2.
Define Central bank.
Answer:
Central bank of any country is the highest financial institution of that country. All other banks of the country work under its guidance. According to bank of international settlements. “The central bank in any country is that which has been entrusted the duty of regulating the volume of currency and credit in the country”.

Question 3.
What do you mean by clearing house of Central bank?
or
How Central bank does the work of clearing house?
Answer:
Clearing house:
Representatives of different banks in a city meet at the clearing house of the Central bank. Payments from one bank to other bank are settled through a simple book of adjustments without involving transfers of funds. Daily differences in the clearing between the banks are adjusted by means of debit and credit entries in their respective account with the Central bank.

Question 4.
Write two advantages and defects of Commercial banks.
Answer:
Following are the two advantages of commercial banks:

1. Use of savings for production purposes:
Banks collects small and big savings of the country and use them for various purposes. Banks provide timely financial assistance to traders and industries. Banks help in the distribution of surplus capital in regions where it is not wanted to those regions where it can be used. Large scale transactions would be quite impossible without banks.

2. Facility of capital transfer:
Banks spend money from one place to another easily in less time. They send it through draft, cheques, etc. For the development economy money can be transferred from one place to another.

Defects of commercial banks:

1. Less banking facilities:
Compare to other countries there are less banking facilities available in India.
Some banks do not get proper guidance and instructions from reserve bank of India. It has unfavourable effect on banking system. So, Indian Commercial banking system has not succeeded in attracking the Indian public.

2. Inefficiency:
Most of the commercial banking systems are unable to provide efficient and quick services to their customers. Moreover in India the distribution of commercial banks are in imbalance way.

Question 5.
Differentiate between Reserve Bank and Commercial Bank.
Answer:
Differences between Reserve Bank and Commercial Bank:

Reserve Bank:

• It is the highest bank of India. It is a controlling bank.
• There is only one central bank (Reserve bank) in India.
• It enjoys the monopoly right for note issue.
• It has no dealing and direct relation with public.
• The ownership of this bank is in the hands of central government.

Commercial Bank:

• It is a part of banking system. It is con trolled by Reserve Bank of India.
• There are many commercial banks in India.
• A commercial bank does not have such right.
• It has direct relation and dealing with public.
• The ownership of this bank is in the hands of government or public.

Question 6.
Why is speculative demand for money inversely related to the rate of interest?
Answer:
Speculative demand for money is made for return in the form of interest. Hence, rate of interest determiners the speculative demand for money of the rate of interest higher the speculative demand for money will be low and vice-versa. The reason is that people will convert their money in bonds when the interest on bond is higher.

In that case, demand for speculative purpose will be low. On the other hand, the rate of interest is lower than the expected interest, people will not convert their money in bonds and keep money in hand for speculative purpose. In this way, a specular demand for money in inversely related to the of interest.

Question 7.
What role of RBI is known as lender of last resort?
Answer:
Lender of last resort:
The Central Bank aslo plays the role of last resort. Lender of last resort means that a Commercial Bank fails to meet his financial requirements from other sources, it can as a last resort, approaches to the Central Bank for loans and advances. The Central Bank consists such bank through discounting of approved securities and bills of exchange. As a last resort, Central Bank exercise control over the entire banking system of the conuntry.

Question 8.
What is liquidity trap?
Answer:
Liquidity Trap:
Everyone in the economy holds his wealth in money balance and if additional money is injected within the economy, it will be used to satiate people’s craving for money balances without increasing the demand for bond and without further lowering the rate of interest below the flow min. Such a situation is called liquidity trap.

Question 9.
What is barter system? What are its defects?
Answer:
Barter system:
Barter system means the exchange of goods and services directly for goods and services. In other words economic exchange without the medium of money is referred to as Barter system.

Drawbacks of barter system : Following are main drawbacks of the barter system:

1. Lack of double coincidence:
The lack of double coincidence of wants is the major drawback. It is very rare when the owner of same goods or service could find some are who wants his good or service and possessed that good service that the first person wanted. No exchange is possible if the double coincidence is not there.

2. Absence of common unit of measurement:
The second main drawback of barter is the absence of a common unit of measurement in which the value of goods and services can be measured. In the absence of a common unit proper accounting system is not possible.

3. Lacks of standard deferred payments:
Thirdly, the barter system lacks any satisfactory unit to engage in contracts involving future payments. In a barter economy future payments would have to be stated in specific goods of services which may involve disagreement over the quality of goods or even on the commodity used for repayment.

4. Lack of storing wealth:
Fourthly, the barter system does not provide for any method of storing purchasing power.

Question 10.
Suppose a bond promises Rs 500 at the end of two years with no intermediate return. If the rate of interest is 5% per annum, what is the price of the bond?
Answer:
= 500 x \(\frac { 1 }{ \left\lceil 1+\frac { 5 }{ 100 } \right\rceil \left\lceil 1+\frac { 5 }{ 100 } \right\rceil } \)
= 500 x \(\frac { 20 }{ 21 }\) x \(\frac { 20 }{ 21 }\)
=\(\frac { 10,000 x 20 }{ 21 x 21 }\)
=\(\frac { 2,00,000}{ 441 }\)
= Rs 453.51.

Micro Economics Money and Banking Long Answer Type Questions

Question 1
What do you mean by stock of money and flow of money?
or
Write the differences between the stock of money and flow of money.
Answer:
Differences between Stock of money and Flow of money:

Stock:

• Stock is related to a point of time.
• A stock is a quantity measurable at a particular point of time such as 10:00 am etc.
• It has no time dimension.
• National capital is stock.
• It is a static concept.

Flow:

• Flow is related to a period of time.
• A flow is a quantity which is measured over a specific period of time such as an hour, a day, a week etc.
• It has time dimension.
• National income is a flow.
• It is a dynamic concept.

Question 2.
Explain five functions of RBI in detail.
Answer:
Followings are the functions of Reserve Bank of India:

1. Issue of currency notes:
The Reserve Bank of India has been given the monopoly of issuing currency notes. At present, it is authorised to issue currency notes in the denomination of Rs. 5,10,20,50,100,500 and 2,000. One rupee note and coins are issued by government of India. The notes issued by R.B.I. are legal currency.

2. Credit control:
The main functions of R.B.I. is to control and regulate volume of credit and currency in India. It controls the credit granted by commercial banks. It controls the credit inflationary impact of the ever increasing development financing in five year plans. R.B.I. controls the credit by increasing or decreasing bank rates buying and selling government securities in the open market, by increasing the cash reserves, by issuing specific directions to banks etc.

3. Banker agent and advisor to government:
The reserve bank of India acts as banker, agent and advisor to the central and state governments. As a banker to government R.B.I. performs many functions. It manages the public debt, makes all payments, receives all the revenues in government account managing foreign exchange, etc. R.B.I. has appointed experts of all fields of specialization who gives proper advice to central and state governments in various matters from time-to-time.

4. Banker’s bank:
R.B.I. is banker to banks in India. It accepts deposits of commercial banks and lends of them from time – to – time. It extends short term loans and advances against eligible securities and promissory notes. It makes purchases and sales of foreign currencies also. The commercial and other banks have to deposit with R.B.I. a certain percentage of their total liabilities to enjoy various facilities from it.

5. Foreign exchange management:
R.B.I. controls all receipts and payments in foreign exchange under F.E.M. A. All payments to be made in foreign exchange exceeding the limit prescribed under the act must seek RBI’s permission.

Question 3.
Explain the methods to control the credit taken by the reserve bank.
Or
Explain how the Reserve Bank of India controls credit.
Answer:
Followings are the methods to control the credit:

1. Bank rate:
The rate at which Reserve Bank of India gives loan to other banks on the basis of securities is called bank rate. R.B.I. increases or decrease the bank rate for reducing or expanding the credit from time-to-time.

2. Activities of open market:
R.B.I. buys and sells the government securities in the open market for expanding and reducing the volume of credit. This is called open market operation. By this activities R.B.I. increases or decreases the amount of money.

3. Changing the ratio of bank’s reserves:
R.B. I. controls the credit by increasing the percentage of cash reserves which is kept by scheduled commercial banks compulsorily with R.B.I.

4. Liquidity ratio-system:
Reserve Bank of India increases or decreases the liquidity ratio for reducing or expanding credit.

5. Selective credit control policy:
Reserve bank adopts the selective credit control policy in respect of certain commodities which have been sensitive.

6. By issuing specific directions to banks:
R.B.I. issues specific directions to banks in general regarding lending rates.

7. Increase or Decrease refinancing facility:
R.B.I. increases or decreases refinancing facility to commercial banks for credit control. Rigid attitude for refinancing reduces credit and liberal attitude for refinancing expands credit.

Question 4.
Suggest some measures to remove the defects of commercial bank.
Answer:
Following steps should be taken to improve the conditions of Indian commercial banks:

1. For the balance development of commercial banks their new branches should be open in villages and backward areas.
2. To solve the problem of shortage of capital the money deposits schemes of the banks should be made attractive.
3. Knowledge and education regarding the banks should be given clearly.
4. For increasing the banking systems the trained and efficient officers should be appointed.
5. Reserve bank should make such rules which will control the corruption in the banking system.
6. Banks should follow the policy of cooperation with other banks instead of following the policy of competition with each other.

Question 5.
Write any five functions of Commercial Banks.
Answer:
Following are the functions of Commercial banks:

I. Primary Functions

1. Acceptance of deposits:
All commercial banks accept money on deposits. By taking money on deposits a bank provides safe keeping for people’s money. For deposition of money a bank provides facility of five types of customer accounts:

• Current account
• Fixed deposit account
• Savings bank account
• Home savings account and
• Recurring deposit account.

2. Lending and Investment:
The second primary function of a bank is to lend money to borrowers bank keeps a part of the total deposits with itself as cash reserves and lends the balance. Bank charges interest on such lending of money, which is also the main source of profit to most of the banks. Money lending may be in the form of overdrafts, cash credits or loans.

II. Subsidiary Functions

In order to provide several kinds of facilities to their customers commercial banks perform many functions. They are as follows:

1. Issuing of credit instruments:
All commercial banks issue various instruments of credit such as bill of exchange, hundi, draft and cheque etc.

2. Arrangement of foreign exchange:
For foreign trade banks convert the currency of one country into the currency of another country. This work is done by exchange Banks.

3. Keeping valuables safely:
Banks provide the facility of lockers for the customers to keep their valuable things gold, diamonds, Jewellary etc. are kept in these lockers.

4. Discounting of bills of exchange and hundies:
Banks discount the bill and hundies of their customers before the date of maturity of such instruments.

5. Collecting payments:
Commercial banks collect payments of their customers bills, cheques and hundies etc. Banks charge commissions for these services.

6. Making payments:
Banks make payments on behalf of their customers. The make payments of installments of loans, interest, donations, insurance etc.They charge nominal commission for their services.

7. Selling and Purchasing of securities:
Commercial banks sell and purchase shares, debentures Govt.bonds etc.

Question 6.
What are the main functions of money? How does money remove the defect of barter system?
Answer:
Followings are the functions of money:

Primary Functions:

1. Medium of exchange:
This is the most important function of money. It acts as a medium of exchange. All the exchanges of goods and services are taken place in terms of money. By paying predetermined price, money can be exchanged with the desired goods and services.

2. Measure of value:
The second basic function of money is that it measures the value of goods and services. In other words, the prices of all goods and services are expressed in terms of money. In ancient times it was not possible of measure the value of clothes and wheat. With the introduction of money this difficulty of measurement disappeared and it became very convinient to measure the value of money. Money acts as a unit of account for all goods, wages salaries, interests etc. The national income, capital formation and other are measured in terms of money.

3. Store of exchange value:
Money can be stored very easily. Money is a liquid form of capital. It require less place to store. There is very less fluctuation in the value of money in comparison to goods. That is why mentry to save a part of their income for future. Money provides a base for store value.

Store of value means store of wealth.People can now keep their wealth in the form of money. Under barter system, storing of wealth was possible only in terms of commodities which had its defects like perishable nature of some goods, cost of storage etc. But storing of value in the form of money has solved all these difficulties. It was Keynes who first realised the store value function of money. He regarded money as link between the present and the future. Money allows us to store purchasing power which can be used at any time in future to purchase goods and services.

4. Transfer of value:
With the economic development the trade and commerce also increased rapidly. This causes the need of transfer of money from one place to another. Sometimes it crosses the national boundary too. Money is a liquid assets so it can be transferred from one place to another.

Through money, value can be easily and quickly transferred from one place to another because money is acceptable everywhere. For example a person can transfer money from Katakana to Delhi through bank draft, bill of exchange etc. Money thus, facilitates movement of wealth and capital. Under barter system it was difficult to transfer value in the from commodities.

Question 7.
Explain the functions of commercial banks. (Any two)
Answer:
Functions of a Commercial Bank:
Following are main functions of a commercial Bank:

1. Acceptance of deposits:
This is an important primary function of the Commercial Banks. The Commercial Banks accept deposits from individuals, business firms and other institutions. This is economically useful function in the sense that it helps in the mobilization of savings for production purposes. The commercial banks accept deposits in several forms according to the requirements of different sections of the society.

2. Advancing of Loans:
Extending loans is another important primary function of the commercial banks. It is also the main source of their income. Traditionally, bankers charged a service charge from the depositors, as they did not use the deposits for lending purposes. Gradually, they realized that.there is no point in keeping all the money which they received from depositors as revenue. All the depositors never approached bankers to withdraw their money at one point of time. In the beginning, their lending out of deposits were confined to short term loans to provide working funds for current business operations.

Now, banks have extended their lending activities to investment in long term bonds. Furthermore, today, commercial banks lend to consumers and government units besides financing trade and industry to meet the divergent needs of their customers. In the manner, they could find safe and lucrative outlets for their funds. The normal performance for banks is for secured loans, but they often give loans to business firms of high credit standing without security. .

Question 8.
What is money multiplier? How will you determine its value?
Answer:
Money multiplier:
Money multiplier may be defined as “the ratio of the stock of money to the stock of high powered money in an economy.” In equation:
Money multiplier = \({ M }{ H }\)
M = Stock of money
H = Stock of high powered money in an economy
The value of money multiplier is greater than 1. The value of money multiplier is determined by applying the following formula:
Money multiplier = \({ 1- cdr }{ cdr – rdr }\)
Method of finding out multiplier
Supply of money = Money + Deposit
M = Cu + DD
= (1 + Cdr) DD
Cdr = Cu / DD
H = Cu + R
= CdrDD + rdr DD
= (Cdr + rdr) DD
Money multiplier = M/H
\(\frac { (1+Cdr)DD }{ (Cdr+rdr)DD }\) = \(\frac { 1+Cdr }{ Cdr+rdr }\)
1 + Cdr > Cdr + rdr.

Question 9.
What are the methods adopted by Reserve Bank of India to regulate the credit?
Answer:
There are those instruments of monetary policy which after overall supply of money / credit in the economy. They are as follows:

1. Bank Rate:
The bank rate is the minimum rate at which the Central Bank of a country (as a lender of last season) is prepared to give credit to the Commercial Bank. The increase in bank rate increases the rate of interest and credit becomes dear. Accordingly, the demand for credit is reduced. On the other hand, decrease in the bank rate lowers the market rate of interest charged by the commercial banks from their borrowers. Credit becomes cheap. The Reserve Bank adopts dear money policy when the supply of credit needs to be reduced during periods of inflation. It adopts cheap money policy when credit needs to be expanded during deflation.

2. Open Market Operations:
Open Market Operations refer to the sale and purchase of securities in the open market by the Central Bank. By selling the securities (like, National Saving Certificates-NSCs), the Central Bank withdraws cash balances from within the economy. And, by buying the securities, the Central Bank contributes to cash balances in the economy.

3. Cash Reserve Ratio (CRR):
It refers to the minimum percentage of a bank’s total deposits required to be keep with the Central Banks. Commercial Banks have to keep with toe Central Bank a certain percentage of their deposits in the form of cash reserves as a matter of law. When the cash flow or credit is to be increased, minimum reserve ratio is reduced and when the cash flow or credit is to be reduced, minimum cash reserve ratio is increased.

4. Statutory Liquidity Ratio (SLR):
Every bank is required to maintain a fixed percentage of its assets in the form of cash or other liquid assets, called SLR. With a view to reducing the flow of credit in the market, the Central Bank increases this liquidity ratio. However, in case of expansion of credit, the liquidity ratio is reduced.

Qualitative Method of Credit Control
Or
Qualitative Instruments of Monetary Policy

1. Margin Requirement:
The margin requirement of loan refers to the difference between the current value of the security offered for loans and the value of loans granted. Suppose, a person mortgages an article worth Rs 100 with the bank and the bank gives him loan of Rs 80. The margin requirement in this case would be 20 percent. In case, the flow of credit is to be restricted for certain specific business activities in the economy, the margin requirement of loan is raised for those very activities. The margin requirement is lowered in case the expansion of credit is desired.

2, Rationing of Credit:
Rationing of credit refers to fixation of credit quotas for different business activities. Rationing of credit is introduced when the flow of credit is to be checked particularly for speculative activities in the economy. The Central Bank fixes credit quota for different business activities. The Commercial Banks cannot exceed the quota limits while granting loans.

MP Board Class 12th Economics Important Questions